Windows 8, Cap6, Publish to Network Folder: Hangs at 50%, no network access until reboot

Using Windows 8 with Captivate 6, this symtpom occurs on two different computers.  We publish files to a network folder, which has worked pretty well since January until this week.   Intermittently, when publishing, a hang occurs at 50%.   There is no network access at this point.  No browsers open pages, etc.  Only recovery so far is to reboot.  Using two different versions of Cap6 (6.0.1.240 & 6.1.0.319).    Any suggestions?