Then something has changed, either in the application, the environment (i.e. the Operating system, perhaps) or the hardware. Given that you can print from Word with no issue, I'd say the least likely suspects are the hardware and environment, and the much MORE likely suspect is the Access database itself. It's almost impossible to tell you what to check, since so many things can cause this.
If you Preview the report within Access, does the same behavior seem to result? That is, the invoices "slip down" the page in Preview mode as well?