6 large source images have thumbnails that aren't rendering

I have a CCK based node setup with six 1000x800 images plus some smaller images, these are then used to generate 544x414 thumbnails.

I have themed the node so that each thumbnail is displayed using:

print theme('imagecache', "my_preset_name", $node->field_my_image[0]['filepath']);

However, the thumbs only appear once the page has been refreshed several times, which I suspect is down to there being too many images to process at once.

I am using ImageCache 5.x-2.1, ImageAPI, 5.x-1.2. I have also installed ImageMagick 6.4.2 and have set ImageCache to use this library. Image compression is set to 85% and memory_limit is 128MB.

Do you have any suggestions to further improve the performance of the module?

My only alternative is too look at modifying the node template so that it refreshes until all images are loaded (messy), or looking into forcing/queueing the images to imagecached in some way (complicated).

Any suggestions welcome!

cheers,

mark