Hi Yep i've witnessed this one loads of times, yesterday was the last time in fact using 7.3cs1(but i've seen it in all versions of PT7). It doesn't seem to affect performance tho' so i've long since given it up as one of those wierd anomalies that happen and it's only slightly irksome! G4 dual 800 1.5gb ram OSX 10.4.6 PT 7.3cs1