punch-in crash

I was recording some singing and meaked a loop area so I could have a lot of takes to choose from. I accidently marked the loop area as punch-in area also, and when recorded two takes SONAR crashed. I managed to reproduce the crash again with FX shut off (I thought that was the problem). The rec was set to comping mode. When I found out what the punch-in was used for I removed that and had no problem recording 5-6 takes in one go. I don't know if you ever need to punch-in twice in a loop sequence but can anyone reproduce this? =) The loop area and the punch-in area was marked exactly the same. Sonar X3C.