I have heard from some people that they are not able to get an Sil3132 based eSATA ExpressCard to see an attached drive. I thought it was just a driver issue until recently I was testing a new Dell Inspiron 1420 notebook and experienced the same issue. I could get the driver to successfully to install on Vista-32, Vista-64, and Windows 2008 RC0. But only Windows 2008 RC0 actually saw an attached disk drive.
I tried everything, updated the firmware of the eSATA card, the latest drivers, different cards (but same 3132 chipset). Nothing worked on Vista-32 or Vista-64.
I decided to download Vista SP1 and try that.....Voila, it worked the first time. It even loaded the latest version of the drivers from Windows Update.
I will try and see if I can find a hotfix that addresses this issue and post it, but wanted to let you know that if you are having this problem, try installing Vista SP1 on a new disk and see if that solves it.
Note that I installed Vista SP1 slipstreamed as part of a new install, I have not tried an upgrade in place.
BTW, if you are trying to get a Sil3132 card to work under Windows 2008 RC0 x64, go to www.siliconimage.com and get the latest drivers from their site. Use the Vista-64 drivers, they work fine....so far ;-)