Do you own a bearcat scanner? I can't remember the IF freq for them right off hand. 10.8 or 10.7? Maybe even 11. something. I had one that was receiving a channel in the 150's range and every time it stopped on that channel it would lock up the 2 meter freq for the duration that it was stopped on the channel! Drove me nuts for a while till I stumbled on it one day. Lock channel out on scanner and problem went away. Just a thought.
Mike KA2NDW