I tried to do this when I first switched to OS X (10.1) using a Belkin device that had OS X drivers with no luck.
If I'm remembering correctly, it had to something to do with Palm Desktop not supporting syncing over the 3rd Party serial-to-usb adapter. I guess it wouldn't recognize the Palm V as a USB device or something.
Any who, the only way I could get my Palm to sync was to use Palm's PalmConnect device.