I've been using 'zaurus-sd-driver-update-cxxxx_1.0_arm' since the ipk was first posted. Pretty much as soon as I read (meanie posted it, I think) that pdaxrom beta1 could use the file. Reflashed to beta1, used the package manager gui to install the ipk to /, and then rebooted. It was a litle hairy when I first inserted my 4GB SD card, my 3100 froze when I put it in, and I pulled the battery. It has been flawless ever since.
Oh, it is an A Data Turbo 4GB, 150x 'MyFlash'. It is dark blue/purple, with a pink label. It is also half the price or less that I paid for it at this time, lol.