It could be a few things. First I would try running it in debug mode and see what kind of error it regurgitates back at you.
Did you activate m_mysql using ./extras before compiling, can you access your database using the mysql command line tool? Unfortunately your question is a bit too broad for anyone to help, if you could perhaps supply a bit more information such as what error messages (if any) you get in debug mode and such that'd help to narrow what the issue might be related to.