microsoft word notebook layout Saving Problems

Hi

I'm having problems with my microsoft word where in notebook layout it won't allow me to save when the ending is docx, which is the usual saving ending. It allows me to save publisher and normal blank word documents, however not the notebook layout. I'm using Snow Leopard and word 2011, have done the updates, and it's the update version of 14.2.3. When i took it to Apple they couldn't help me besides telling me that maybe i have a corrupted file on my laptop and that i should make a new user and transfer my files over. However, if there is a corrupted file then it would just go onto the new user and it also doesn't allow me to prevent it, if the saving problems happen again.

Has anyone seen this or does anyone know how to fix this problem? Could it be a virus or a corrupted file? And if it's a corrupted file how do i find it to delete it?

Thanks if anyone could help.