Recently I downloaded and installed S5500 Based Server AHCI SATA Storage Driver for Windows on my Acer Aspire 6935G (with Win7 x64) and noticed following issue: some newly created files were unreadable (when I tried to copy them, progress stopped at some point, then I waited some time until I got error). When I rewrited those files with newly downloaded, everything have been reading fine. I had multiple issues like that. When I unistalled that driver and returned to Win7 x64 built-in, issues stopped.
Or if anyone knows where should I report about this problem (firstname.lastname@example.org is not an option - no one reads emails there), please write where to.
PS: It's also good idea to make "safe eject" option for driver (for eSata interface safe eject for example, like Windows 7 generic SATA driver)