sending bad packets

I have alot of problems on my network. But my current issue is that some users cannot save changes made to word documents in a shared folder, even though they are allowed to open and edit the file. The message they get is that"..cannot save due to afile permission error". Microsoft article (Q278456) says that the reason is that client machine sends a bad packet to the server.
What would cause a machine to send a bad packet ?
And could this be the cause of network printing problems ?