Hi there,
Per our conversation in-game a couple things to try:
1) Running your EQGame.exe client in comparability mode for a different version of windows.
2) If that doesn't work, you can try installing patch 49c and seeing if that's any better (Link:
http://www.project1999.com/files/P99Files49c.zip)
Please let us know how it goes!
Guide Medris