For me it's obvious that your problem is localize because 99% of people are connecting without any problems...
You should provide more information like
Dedicated or not...
What DB management program is used...
Specs of the machine...
More precision on the error and when it occurs...
Screenshots!!!
... and not let your thread die to oblivion for 2 weeks...
I might not have the answer your are looking for but lots of good admins are lurking around the forums from time to time... give yourself a chance to get helped...