Hundreds of extra images created

I have ~3000 images on my site, mostly added using the import functionality, and I navigate them using the acidfree module.
Everything works well, but it has always bothered me that all images get uploaded to the same folder since I have lots more images to add.

I hadn't looked closely at my folder listing until yesterday when I saw something alarming:
For these 3000 images, my folder listing is 56 megs long!

It seems that a bunch of extra images are created everytime an image is viewed, so some images have hundreds of extra files.

For example, I have an image called 0036msms.jpg
I would exepect the regular preview, thumbnail, big-thumbnail, small-thumbnail, and gal-thumbnail images to be created. But the listing shows an extra 35x5 preview_xx images created as follows - How do I stop this insanity?

Please help,
Ktnk.
PS: I cannot update to the more recent version of the module because of issue # 262881

0036msms.big-thumbnail.jpg
0036msms.gal-thumbnail.jpg
0036msms.jpg
0036msms.preview_0.big-thumbnail.jpg
0036msms.preview_0.gal-thumbnail.jpg
0036msms.preview_0.jpg
0036msms.preview_0.small-thumbnail.jpg
0036msms.preview_10.big-thumbnail.jpg
0036msms.preview_10.gal-thumbnail.jpg
0036msms.preview_10.jpg
0036msms.preview_10.small-thumbnail.jpg
0036msms.preview_11.big-thumbnail.jpg
0036msms.preview_11.gal-thumbnail.jpg
0036msms.preview_11.jpg
0036msms.preview_11.small-thumbnail.jpg
0036msms.preview_12.big-thumbnail.jpg
0036msms.preview_12.gal-thumbnail.jpg
0036msms.preview_12.jpg
0036msms.preview_12.small-thumbnail.jpg
0036msms.preview_13.big-thumbnail.jpg
0036msms.preview_13.gal-thumbnail.jpg
0036msms.preview_13.jpg
0036msms.preview_13.small-thumbnail.jpg
0036msms.preview_14.big-thumbnail.jpg
0036msms.preview_14.gal-thumbnail.jpg
0036msms.preview_14.jpg
0036msms.preview_14.small-thumbnail.jpg
0036msms.preview_15.big-thumbnail.jpg
0036msms.preview_15.gal-thumbnail.jpg
0036msms.preview_15.jpg
0036msms.preview_15.small-thumbnail.jpg
0036msms.preview_16.big-thumbnail.jpg
0036msms.preview_16.gal-thumbnail.jpg
0036msms.preview_16.jpg
0036msms.preview_16.small-thumbnail.jpg
0036msms.preview_17.big-thumbnail.jpg
0036msms.preview_17.gal-thumbnail.jpg
0036msms.preview_17.jpg
0036msms.preview_17.small-thumbnail.jpg
0036msms.preview_18.big-thumbnail.jpg
0036msms.preview_18.gal-thumbnail.jpg
0036msms.preview_18.jpg
0036msms.preview_18.small-thumbnail.jpg
0036msms.preview_19.big-thumbnail.jpg
0036msms.preview_19.gal-thumbnail.jpg
0036msms.preview_19.jpg
0036msms.preview_19.small-thumbnail.jpg
0036msms.preview_1.big-thumbnail.jpg
0036msms.preview_1.gal-thumbnail.jpg
0036msms.preview_1.jpg
0036msms.preview_1.small-thumbnail.jpg
0036msms.preview_20.big-thumbnail.jpg
0036msms.preview_20.gal-thumbnail.jpg
0036msms.preview_20.jpg
0036msms.preview_20.small-thumbnail.jpg
0036msms.preview_21.big-thumbnail.jpg
0036msms.preview_21.gal-thumbnail.jpg
0036msms.preview_21.jpg
0036msms.preview_21.small-thumbnail.jpg
0036msms.preview_22.big-thumbnail.jpg
0036msms.preview_22.gal-thumbnail.jpg
0036msms.preview_22.jpg
0036msms.preview_22.small-thumbnail.jpg
0036msms.preview_23.big-thumbnail.jpg
0036msms.preview_23.gal-thumbnail.jpg
0036msms.preview_23.jpg
0036msms.preview_23.small-thumbnail.jpg
0036msms.preview_24.big-thumbnail.jpg
0036msms.preview_24.gal-thumbnail.jpg
0036msms.preview_24.jpg
0036msms.preview_24.small-thumbnail.jpg
0036msms.preview_25.big-thumbnail.jpg
0036msms.preview_25.gal-thumbnail.jpg
0036msms.preview_25.jpg
0036msms.preview_25.small-thumbnail.jpg
0036msms.preview_26.big-thumbnail.jpg
0036msms.preview_26.gal-thumbnail.jpg
0036msms.preview_26.jpg
0036msms.preview_26.small-thumbnail.jpg
0036msms.preview_27.big-thumbnail.jpg
0036msms.preview_27.gal-thumbnail.jpg
0036msms.preview_27.jpg
0036msms.preview_27.small-thumbnail.jpg
0036msms.preview_28.big-thumbnail.jpg
0036msms.preview_28.gal-thumbnail.jpg
0036msms.preview_28.jpg
0036msms.preview_28.small-thumbnail.jpg
0036msms.preview_29.big-thumbnail.jpg
0036msms.preview_29.gal-thumbnail.jpg
0036msms.preview_29.jpg
0036msms.preview_29.small-thumbnail.jpg
0036msms.preview_2.big-thumbnail.jpg
0036msms.preview_2.gal-thumbnail.jpg
0036msms.preview_2.jpg
0036msms.preview_2.small-thumbnail.jpg
0036msms.preview_30.big-thumbnail.jpg
0036msms.preview_30.gal-thumbnail.jpg
0036msms.preview_30.jpg
0036msms.preview_30.small-thumbnail.jpg
0036msms.preview_31.big-thumbnail.jpg
0036msms.preview_31.gal-thumbnail.jpg
0036msms.preview_31.jpg
0036msms.preview_31.small-thumbnail.jpg
0036msms.preview_32.big-thumbnail.jpg
0036msms.preview_32.gal-thumbnail.jpg
0036msms.preview_32.jpg
0036msms.preview_32.small-thumbnail.jpg
0036msms.preview_33.big-thumbnail.jpg
0036msms.preview_33.gal-thumbnail.jpg
0036msms.preview_33.jpg
0036msms.preview_33.small-thumbnail.jpg
0036msms.preview_34.big-thumbnail.jpg
0036msms.preview_34.gal-thumbnail.jpg
0036msms.preview_34.jpg
0036msms.preview_34.small-thumbnail.jpg
0036msms.preview_35.big-thumbnail.jpg
0036msms.preview_35.gal-thumbnail.jpg
0036msms.preview_35.jpg
0036msms.preview_35.small-thumbnail.jpg
0036msms.preview_3.big-thumbnail.jpg
0036msms.preview_3.gal-thumbnail.jpg
0036msms.preview_3.jpg
0036msms.preview_3.small-thumbnail.jpg
0036msms.preview_4.big-thumbnail.jpg
0036msms.preview_4.gal-thumbnail.jpg
0036msms.preview_4.jpg
0036msms.preview_4.small-thumbnail.jpg
0036msms.preview_5.big-thumbnail.jpg
0036msms.preview_5.gal-thumbnail.jpg
0036msms.preview_5.jpg
0036msms.preview_5.small-thumbnail.jpg
0036msms.preview_6.big-thumbnail.jpg
0036msms.preview_6.gal-thumbnail.jpg
0036msms.preview_6.jpg
0036msms.preview_6.small-thumbnail.jpg
0036msms.preview_7.big-thumbnail.jpg
0036msms.preview_7.gal-thumbnail.jpg
0036msms.preview_7.jpg
0036msms.preview_7.small-thumbnail.jpg
0036msms.preview_8.big-thumbnail.jpg
0036msms.preview_8.gal-thumbnail.jpg
0036msms.preview_8.jpg
0036msms.preview_8.small-thumbnail.jpg
0036msms.preview_9.big-thumbnail.jpg
0036msms.preview_9.gal-thumbnail.jpg
0036msms.preview_9.jpg
0036msms.preview_9.small-thumbnail.jpg
0036msms.preview.jpg
0036msms.small-thumbnail.jpg
0036msms.thumbnail.jpg