Have a Sennheiser EW100 G2. Need to find a compatable receiver for our video Camera. Any help would be greatly appreciated.

Go for the EK 100 G3 receiver - it's diversity (G2 wasn't) and fully compatible with the G2 you have.

I thought that the G2 and G3 used different frequencies and weren't compatible?

Block 'A' in the G3 spans 516...558, The Block 'A' G2 518..554 (approximately, as I recall.)

I just seem to recall Sennheiser saying that the two units were not interchangeable, as the G3 used a different bandwidth.
This seemed odd to me a you should still be able to scan for available frequencies and manually put them in if needed.

Maybe Sennheiser was talking about the programed channels in the unit itself?

I thought that the G2 and G3 used different frequencies and weren't compatible?

No, not true.

All evolution is compatible with each other - G1, G2, G3 and 2000 series.

As you go up, the tuning window gets larger, so you have to choose a frequency in the window of the older unit:
G1 = 24 MHz
G2 = 36 MHz
G3 = 42 Mhz
2000 = 72 MHz

Version for version pretty well all the frequencies in the older unit are in the newer - if any problem there is always the user bank.

So - no problem at all.