Windows 7: can open a file on a network share but can't save file back

I have a Windows 7 Home premium attached to a small network and am accessing network shares on a windows 2993 server. I have set up an associated user and password on the server. The user has a mapped drive to her user documents as well as access to other shares and the data associated there. I set up security permissions and have had the user working properly. UNTIL the other day when she lost the connection to the server and received error messages whe she tried to save the documents she was working on. Now when she logs on, all mapped drive appear and she can open any of the documents but is unable to save them. She can copy the document to her desktop but if she tries to drag and drop the file back to it's location on the network share, but this process ends with error messages. I have created the user on another windows 7 machine and can access the network shares and copy to and from the share without problems. I have also tried to access the files through another user account that has access to those shares and have the same results. It appears that some how, the permissions the computer thinks it has are interfering with the correct permissions. I tried a system restore prior to the date of the failure with no success. Since it will work on another machine, I don't suspect problems with the server. It's localized to the windows 7 box. I've rune chckdsk /f as well as sfc /scannow. Niether solved the problem. Windows 7 is uptodate with all it's patches. This is not a Domain network it is a simple workgroup. Any help would be greatly appreciated