I can't remember what happened two hours ago (as evidenced in the Football Commentators thread in the Broadcasting section last night), so don't feel too worried about forgetting something that happened two years ago.
The list I posted above demonstrates just how Chelsea's local radio commentaries have bounced from one station to the next after talkSPORT ended their five season foray into regional opt-out commentaries in 2006.
I believe GMG Radio signed a non-exclusive three season deal for Smooth FM to do Chelsea commentaries in 2005, but in March 2007 they rebranded and reformatted Smooth and stuck the final year of their deal on sister station Real Radio.
I would have assumed BBC London had a three season deal with Chelsea as well, but I guess they went in with the option of renewing rights on a yearly basis, as talkSPORT did towards the end of their regional commentary run (IIRC they had three season deals for Chelsea, Fulham and Tottenham games between 2001/02 and 2003/04, then brought regional rights to Arsenal, Chelsea, Crystal Palace, Blackburn, Everton and Manchester City in 2004/05, before just renewing Arsenal and Chelsea rights in 2005/06).
Have Arsenal even had a local radio commentary partner since talkSPORT stopped doing their domestic commentaries on 1089am in the South-East?