Odd situation; stuck at verifying account.

[Yukiko]

Here is my problem: Sometimes I get stuck at verifying account when I try to log in. It happened to one of my staff as well. The only solution seemed to be to restart the shard. After the restart then login was successful. I thought that perhaps POL was running heavy but when I checked the sysload on the console it was at zero. I am using client 5.0.4c (Patch 31) so I am certain it isn't a "black hole" issue. I am running POL 0.97 latest release. If anyone has any ideas, I'd appreeciate the help.