Realtek HD detecting rear speaker as side (5.1)

Hi,

Ive just recently switched from vista64 to windows 7 64.

The thing is that im using logitech X-540 5.1 speakers but realtek HD is detecting my "rear" speakers as "side" speakers when I select the 5.1 option. Same thing happened in vista too.

The only way round this to select the 7.1 option and disable the "side" speakers and hence I can use "rear". The sound from the "side" speakers then comes from the ones in the front in the testing.

Now the problem is that when I play games/movies in 5.1 it probably detects my system as a 7.1 and some sound will be missing.

So how can I use the 5.1 option and keep my surround speakers as "rear" and not "side".

Thanks in advance,

P.S. Buying a new soundcard isnt an option for me.

With the realtech software doesnt it ask you what you plugged in? and then you tell it thats its Rear not Side?

here are 2 pics to show my problem