Can someone verify  that the key fobs with the red light are all older type infra red operated and are incompatible with the later radio transponder system please?.

I bought a replacement of Ebay as a spare, it was the same as mine (no red light) but was broken inside, the seller has sent me another one, identical fob  except this one has the red light, I think I am correct in thinking this will not work with my car?

And yours is a later car than mine, a facelift?
In an earlier posting it was said that the infra red ones were replaced in 1994/5 and all subsequent Omegas have readio operated systems, and the fobs with the red lights dont work with these later systems, do some radio transponder ones then have a red light also?  this was actually the point of my post, if ALL  those with a red light are infra red and incompatible with mine?

On the top of the key, half way down by the side of the buttons, a small round red light that flashes on when you press either of the buttons. I thought only infra red systems had this? Or did they start to fit it to later systems as a means of verifying that the battery was ok and a signal was being sent?
If this is the case then this key may work with my car.

I've just phoned the dealers and spoken to their auto electrician and he says some had a light and some didn't, to know if it's compatible with my car he needs to check it inside...so it could be, also he said some Omega's (very few) were made without an alarm system and the key for those is not campatible with the key for systems with an alarm.

They are two button types, I don't really want to open mine up as it's the only one I have, thats why I'm trying to get a spare sorted out.

  Just done a check, If I open my car with the key I can open the door and no alarm! so it looks like I have one of the few with no alarm fitted, which means less availability of compatible keys, so chances are this one won't work, I think I will have top go and let them check it at the dealers to be sure. Also think I will be better getting a key exactly the same as my original one with no red light first.

Take a look here

http://www.omegaowners.com/forum/YaBB.pl?num=1216833667

This says 3 buuton types, mine is two button, either way, my car has no factory fitted alarm system. I wish I had realised this before, as I don't really have a need of a new programmed fob, it's only to lock and unlock the doors, which I can do with a spare key cut as a back up, and I already have a blank.

And fitting an aftermarket alarm will come with it's own remote. Ah well!...you live and learn

Thanks for all the help and input guys.