That sounds odd, I don't have that happen to me so I guess the first thing to see is if you change a few settings in your eqclient.ini file (open wth notepad).
Save a copy of your current one somewhere else in case changing anything makes something worse.
Then have a look down the bottom of the file, you'll see this kind of thing...
Quote:
MouseSensitivity=8
BadWord=1
Anonymous=1
Trade=2
GuildInvites=1
Sky=1
ParticleDensity=3
LoD=1
SameResolution=1
PCNames=1
NPCNames=1
InverseMouse=0
LookSpring=0
MouseActive=1
Destroy=0
AANoConfirm=0
pointMerchantNoConfirm=0
MouseWheelZoom=1
MouseRightHanded=1
|
Try changing a couple of values there, or press ALT+O and play with your mouse settings on the relevant tab.
Other than that, simply... what happens if you unplug your mouse from the usb port and plug it back in? Could be a ghetto fix while looking for something more permanent.