[RESOLVED] "arrow"(corsor) dissappears from screen

My "arrow" suddenly disappears completely from the (active PORTION of screen) after about two hours of surfing the net. It will only become "visable" (reappears) when I move the mouse onto the to the "start" bar (task bar).
Moving the intellimouse back again towards the center of the screen, it again disappears. I have to then use the "sonar" (Ctrl key)to approximate the cursor position in order to back out and close the applications, go off line, and then restart the computer. Upon restart, everything is OK for about two more hours.
If I don't restart,or if I attempt to (used the "sonar" in place of the disappeared arrow) the system then locks up after about 15 more minutes, from apparent lack of rescorces.
WIN'98 I.E.4.10 A.O.L. 4.0
I have 128mb of RAM, a 8mb STB video card and a 10gb h.d. on a pentium II 400mhz