The manual is not an easy read, and I haven't figured everything out yet. My Cobra flashed the word "CEILING" at me towards the end of my second dive last Sunday. By the time I got to my safety stop it disapeared. When I looked at the Cobra in logbook mode and later downloaded into Suunto Dive Manager I saw no record of it. Unfortunately I didn't pay enough attention to notice the ceiling depth it was telling me.
According to my graph, it looks like I got the SLOW indicator early on in my dive, so I'm guessing that's what the CEILING notification was about. I obviously kept under the ceiling for the allotted time, as the computer didn't complain any further.
Don't beat me up too much on my ascent rate... I'm still working on my bouyancy skills, and in my defense I was chasing an erant buddy.
Another user's manual complaint I have is about the tissue loading. I haven't found much information about what the heck that's about. According to the Dive Manager manual, it says to read the Cobra manual and consult your Dive Shop. The only useful tidbit I gleaned is that you don't want any tissue grouping to exceed 100% - if it does you'll go into deco mode.