Ooh, the much coveted V4b...
Yes, you will need a new BIOS before anything else. Easiest way is to buy a new chip; otherwise, you'll have to load a hard-drive with the "AnyISP" sandisk image and trick your IOpener into using it as "D:". The AnyISP image (well, the version I used to publish anyway) was cracked to allow you to get into the shell and flash the BIOS via QNXFlash.
Unfortunately, anything newer than a V2 won't allow those old tricks to gain access into QNX. If you really want to play with QNX on the Sandisk, you'll need to figure out how to copy an older or unlocked distribution (such as the "AnyISP" image) onto the Sandisk. It's actually a very respectable software/os distribution. Too bad the application built upon it (The IOpener GUI) isn't supported anymore.