Apple has acknowledged issues with the trackpads on new PowerBook G4 models and has posted a tech note with a workaround.
"If you find that the trackpad cursor on your PowerBook G4 (12-inch 1.5GHz), PowerBook G4 (15-inch 1.67/1.5GHz), or PowerBook G4 (17-inch 1.67GHz) temporarily stops tracking or behaves erratically, try the following steps to resolve the issue:
1. Make sure you test all parts of the trackpad surface and be sure youire using just one finger. Multiple fingers could cause erratic behavior.
2. Reset the trackpad by placing your entire palm directly onto the whole trackpad for 3 to 4 seconds, and then remove your hand from the trackpad in one smooth motion.
"In most cases, trackpad operation will return to normal," Apple says. "If so, this resolution should work if you ever see the issue again. Apple is aware of this issue and is investigating."
Yesterday we noted a MacFixIt special report tracking issues with the new PowerBooks.