At times like this, nothing beats a good backup. In fact make a complete
backup of your database now and put it away for safe keeping.
That kind of error is often database corruption OR a problem with Access
itself. Is this "cancel" button the X on the report or something created on a
form or menu? Is it the Close Print Preview button? If something created by
you, check the code behind that button.
Do you have the latest service pack installed. Office 2007 is up to SP1. Go
to the Office Button then select the Access Options button towards the lower
right of the pop-up. Next go down to Resources and see if it says SP1 in the
small print under the "about Microsoft Office Access 2007 line.
If it's corruption, below are some resources.
Tony Toews has an excellent web page on database corruption.
http://www.granite.ab.ca/access/corruptmdbs.htm
Allen Brown also has excellent info on corruption.
http://allenbrowne.com/ser-47.html
I have a white paper in a Word document named Fix Corrupt Access Database
towards the bottom this page:
http://www.rogersaccesslibrary.com/OtherLibraries.asp