OK, first off, is your Sansa an R series? To check, go to Settings->Mode
If it says "Rhapsody" and "PlaysForSure", it's an R series.
If it says "MSC" and "MTP", it's a vanilla one.
Also, check your firmware version. If it is 3.x.x.x, it's a v2. If it's 1.x.x.x, it's a v1.