Carlos, we've been using it in the office all year with 0% unplanned downtime. In this respect it seems as solid as SQL Server. FWIW, MySQL is the default database for the Trixbox software pbx installed on all sorts of hardware, including decade-old PIIIs. If you google "mysql problem trixbox" you'll see the problems are mostly password/config related, not stability or reliability.
What sort of trouble are you having?
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
