Martin Husemann wrote:

"You need to tell us a bit more details: what version of NetBSD areyou 
using, what kind of mouse (how is it connected - PS/2 connector,USB, or 
anything else?). What kind of machine are you using - i386 PC?"

It's an old dell machine i386 with a PS/2 connector.  It's NetBSD 3.0, 
could 3.01 make any difference? Maybe it's possible to let cron update 
the mousedriver each 10 seconds or something? There is usb connections 
on the computer, would it change anything if I fix a usb connected mouse?

"Can you check the output of "dmesg" at this point? Does it mention anything
about the mouse? Does unplugging and repluging the mouse fix the problem?
Does just returning to X (via ctrl-alt-F5) fix it?"

The dmesg looks normal and dont show anything special about the mouse. 
Thanks for the tip with ctrl-alt-F5, it was something new for me. I'm 
more experienced with the textmode but other users on the computer would 
scream loud if I suggest lynx and mutt as an option :-)

Thanx for taking time Martin.

/Cheers