problems with mouse pointer

[Sergio Anefalos Pereira <saperei baitaca ipen br>]

Hi everybody !
It is my first time in this list and I am a beginner in Linux systems.
Unfortunately I am having some problem and I have no idea how to fix it.
I'm using RedHat 6.2 and a PS/2 mouse. When a changed the screen
resolution from
600x400 to 800x600 using Xconfigurator, the mouse pointer disappeared
and what I have now is a white square of
2 x 2 cm. It moves exactly like the mouse pointer and it works like it.
The upper left corner activates links and icons. But it's impossible to
work with this square. I have tried to change the mouse (to serial one)
and reinstall it. In text window mode, it seems to work well, but in the
xwindow mode it is terrible. The only thing that I wouldn't like to do
is reinstall the Linux. I have many programs and other stuff.
So please, does anyone could help me ?????
Thank you for your attention,
Sergio