EVE Online announced on their forums that they released a patch earlier this week to help with some client issues that a few folks might be having.

An optional patch was deployed today that addresses issue some players have had with running multiple clients simultaneously. If you’re used to running two or more clients at once and have had trouble in the past, please apply the optional patch, try it out and discuss how it works in this forum thread. Feedback is appreciated and if you run into trouble please remember to file a bugreport and attach a logfile of the run. Keep in mind that you can always install or uninstall optional patches through the ESC menu.

It is recommended to set resource cache size in the settings menu to low, or even off when using multiple clients.

Hopefully this will fix any problems you guys have been having!