I am also using FCamera and BlessN900 with KP53. BlessN900 crashes sometimes, but mostly both of them work. I think I might have had some problems with installing FCamera. Maybe it was about the driver, but can't remember precisely. Anyway I got it working somehow just by reinstalling, without needing to recompile anything.

edit: but obviously I don't have libc6 or other oddities, so that might be the cause.