You did not say which version of Approach you are using. The only releases tested by IBM/Lotus on XP are 9.7 and 9.8.
Another thing that changes with XP vs 2000 is your printer driver. Even if you kept the same printer, the driver will not be the same. Try installing the HP Laserjet IIP driver and set it as your default to see if that changes Approach's behaviour.
Finally, if you got a new computer you may have also increased the screen resolution. Experiment with a lower screen resolution to see if that changes the situation.
Report back on your experience with the above.
Sue Sloan