Remember, the database is definitive. Reality is frequently inaccurate (thank you Douglas Adams).
In other words, the database does not "lose" skills, xp, or build. It's easy to blame the technology, but save for one incredibly unfortunate instance of data corruption a few years back (that cost several days of reconstruction and a fight with the Alliance that goes on even today), every instance of errors reported has been caused by either user error (overwriting one copy of the database with another, failing to update someone's build, etc) or player error (yes, we *did* give you build, and it *is* reflected in your current build total, despite what you seem to think).
I guess what I'm saying is that while the database *does* have its flaws, frequent data loss isn't one of them. All of the advice so far in this thread is sound proof against the two types of errors I mentioned above, so do heed it, but please for the love of build stop blaming the database.