Sharepoint Infopath Cannot Save The Form

A user complained that they could not save a form to an info path library in Sharepoint 2010. The error that they recived was

"InfoPath cannot save the form. The specified location cannot be accessed. Check that the location you entered is correct and that you have appropiate permissions."

I checked the user's permissions and found no problem but every time he tried to save the form he got the error. He was the only person with the problem and trying it on a different PC didn't solve anything. I checked the library to see if there was a previous file that had not being checked in but there was no sign in there. 

Eventually I got him to try saving it with a different name and it worked without any problem. There was no sign of the file with the old name in the recycle bin or anywhere in the library, so it seems like a bug but the workaround was to name the file differently.