Cursor moves with mouse

Hello,

I have a strange problem that is difficult for me to discribe (so the 
subject ist not optimal...):

I have the speedbar left of my xemacs window:

####  +++++++++++++++++++
####  +++++++++++++++++++
####  +++++++++++++++++++
####  +++++++++++++++++++
####  +++++++++++++++++++
####  +++++++++++++++++++

(# = speedbar, + = xemacs )

Now when I just move (no mouseclick, no nothing) the mouse from left to 
right, from speedbar to xemacs, the cursor is moved to the location where 
the mouse movement stops.

For example:

Cursor is in Line 1, Column 10
I move the mouse over the speedbar window.
There I move the mouse down 5 lines.
Then I move the mouse right. If I stop this movement in column 20, the 
cursor is now at Line 6, column 20 ...

This is a quite disturbing -- is there a way to let the cursor where it 
belongs ?

BTW: Are here any speedbar users, besides me ?

Many thanks,

Markus Grunwald
Softwareentwicklung

PRÜFTECHNIK Condition Monitoring GmbH
Oskar-Messter-Straße 19-21
85737 Ismaning
www.pruftechnik.com
Tel: +49 (0)89 99616177
Fax: +49 (0)89 99616200