I encountered this issue today with OW 5.9.2 (sneakypeek 591). Basically, I opened OW and scroll bars didn't display in either of my tabs (restored as part of saved workspace). I restarted OW and everything was fine. I haven't been able to reproduce this, so I can't even speculate as to what caused it. The two tabs contained sites that I visit on a daily basis with no issues, so I suspect it's not specific to the sites. Has anyone else encountered this issue?