I had one heck of a time with my Epson scanner with Snow Leopard. The driver supplied by Apple did not work, nor did the "updated Snow Leopard" driver on Epson's website. Scans came out garbled, like they had gone through a shredder. Image Capture refused to use my old TWAIN driver that I had used for years with PowerPC Macs, running 10.5, 10.4, 10.3, and 10.2.
I finally found a solution. I got GraphicConverter, and set it to open using Rosetta. It found my old PowerPC TWAIN driver and I could then scan again. Perhaps this will work for you too!