This has been a frequent question on these forums and searching for it will yield all those threads, however I can't recall a reliable solution.
Have you tried upgrading your MySQL client libraries so everything uses the latest version or those that came with your MySQL distribution?
If you still don't have any luck and nobody else has any other ideas to this persistant problem you might consider contacting directadmin. Once the problem is sorted out the solution would be very helpful for future reference when anybody else has this problem.