I had the same problem, so I found a workaround!
I use jpg and png only for my products now, but I installed a contribution to set the default image in a category and product.
default_image_in_products_and_categories_v1.0
instead of using default.gif I just used default.jpg (a 1x1 pixel white jpg)
I used both optional database additions, and on step 6 there are 2 options, I used the first option: not relying on any chmods
I have a question though, how do I remove the 'NEW' on the 1st page? Its kinda a filler. And is there a way to add my store logo there instead?
Thanks!