White Page of Death after 5.x-1.7 to 5.x-2.4

I have been trying to update 5.x-1.7 to 5.x-2.4 but experiencing numerous problems. The worst is many pages, but not all, goes White Page of Death. I have 128MB assigned to PHP so I don't think this is a memory issue. If I go back to 5.x-1.7, everything works just fine.

The other problem is, where the page isn't White Page of Death, some of the thumbnails shows up in main image size. I then noticed the path is quite screwed up. The path for thumbnail as I now have is:

mysite.com/sites/default/files/imagecache/thumbnail/sites/default/files/imagecache/schedule_img/filename.jpeg

ImageCache seems to create duplicated directory layer. I used CCK image_field, and the path I entered there for this example is 'shedule_img'.

Please advise.

-Hiro