Cursor in wrong region

Hi everyone,

I have cubase 5, running it on a mac server edition desktop (10.6.5)

I have had no processing problems other than when I run heavy reverb in REverence

I haven’t had any problems with the cursor for a whole year, then once in a while the cursor was placing itself one beat (in 4/4 time) (I think, I don’t know music terminology) behind where it should be. This wasn’t a big problem as when I double clicked on a spot to start the music, the sound would correspond with where I clicked. However, now the cursor is 2 measures behind where it should be, and when I click to play at a specific region, the sound does not correspond correctly (it corresponds to information two bars later).

Is this a bug, do you think it has to do with processing speed (i.e. computer), what do you think?