Why don't you try using the cab file? You can get it here:
http://69.0.238.8/soft/reader5/mobireader.arm.cab
Download the file and transfer it over to your PDA. Just click on the file on your PDA, and it will automatically install.
If you wish to install on a storage card, get
cabinstl.
You'll miss out on the desktop reader and autosync, but at least you'll be able to read on your device.