This has happened to me a few times now.
Column 1 on every deck is left open, with persistent clips in all the column 1 rows assigned from my 1st deck (access always to my default show look).
Will work fine for a while, and dosen't always do this, but a some point my persistent clips will start dissapearing as I switch decks, a potentially show stopping error.
It happens so inconsistently it's very hard to diagnose the cause. This a known problem/happened to anyone else?