I don't know if this is related but I just edit clips in one lane. If I have to record a portion of a part over, I take out what I messed up on and just blend in what I play again.
So, I have two seperated clips that I want. I have to go back to a point before those two clips and re-record what I messed up. What should happen is I select the clips I recorded and put the now time where I want and split the clips (I record two tracks. One effected, one dry) and you would think I could just delete the previous unneeded intro. For some reason, the two clips before somehow combined with the re-recorded clips. Even wierder still, sometimes I can crop the clip and everthing will be fine and sometimes the previous clips will crop away with the re-recorded clips. It's all very strange. If it happens again, I'll try and remember to do a screen capture.
Yes, annoying!