I just got EPSON 4990 Pro to replace my old scanner. Using Epson Scan for 6x6 and 4x5 slides, somehow I could not be able to use the thumbnail preview but got a error message " not enough vailable memory". My system is P4, 33.0 GHz, 1.5GB RAM, 3GB virtual RAM, and 1TB HD space, even I used 96dpi resolution still got the same error. This never happened when I scan a batch of 35mm mounted slides even with 4800 dpi, the thumbnail preview just worked fine. I came across a post from a forum that mentioned the same problem for larger size film than 35mm. Is there anyone has same problem or a solution to work around? Thanks.