Unable to Save Presentation

[yoel]

Hi,
I am a regular worker with powerpoint, and a new problem has cropped up: I try to save, and get the following message: "There was an error accessing" with the pathname of the file following.
I can resolve the problem by saving the file under a different name every time I need to save, but this is a hassle.
I use Office Professional Plus 2010, and ppt 14.
Attaching the presentation. Please not that it started causing trouble with the first slide.


Other relevant information (perhaps): I recently started working with Dropbox inside Google Drive. Until then I had worked with Dropbox alone. Could this be in any way relevant?
Any tips will be appreciated...