NIS 2010 and networked drive NAS

Hello, I have installed NIS 2010 on Windows 7 64bit.  I also have a networked drive mapped NAS.  Whenever I try to access some files on the NAS, it is very slow.  When I right click on the file, it freeze up my entire system.  When I disabled the NIS antivirus protection, everything works perfectly fine with no delays or freezing so I know it's definitely the NIS acting upon this problem.  Is this a bug with network drive?  I have searched and found no relevent support for this issue.