gcc (Ubuntu 4.3.3-5ubuntu4) 4.3.3
....src/libfreepv/QTVRDecoder.cpp:386:14: warning: multi-character character constant
It means it's found a character constant with single quotes, but more tahn one character between the quotes.
I manually found 'vide' in that source file. I suspect the compiler will treat this as 'v', which would then be promoted to a string for the assingment.
gcc-3.x doesn't warn is not a reason not to fix it. Gcc-3.x is silently compiling the code into something you didn't intend to do. It's still a bug.
grep "'...*'" src/libfreepv/QTVRDecoder.cpp
or other source files will show you where this happens.