Inactive contact changes group by itself

[Mymac4ever]

One of my contacts keeps changing group all by itself. I usualy notice this move after I've started up Adium. I then move the contact back to its original group by changing the setting under get info>accounts>

I've so far only experienced this problem with one contact. I think I've tried removing the contact and adding it again to the proper group but it doesn't make any difference.

Might also be that this occurs everytime the particular contact changes status but so far I've only seen it occur (well actually seen the effect of it) after I've restarted Adium. It doesn't matter how many times I change the group for this contact - it just keeps moving back to where it shouldn't be. It's anoying if nothing else.