Programs Freezing In Windows 7 - Security Settings Maybe?

I think it may be a security policy setting on the PC. The issue is that I had to change some settings because we access a UNIX server for our old ERP, a Windows Server2008 for our new ERP, and use Windows Server2003s for our VPN, File and Domain controllers. For workstations we have a mix of XP, and Win7 machines. The only computers having issues are the Win7 machines. We use Dell Vostro 460's, doubt the stats are really necessary. But they run Win7 Professional 64-bit.So I had to flip the following settings to communicate with the UNIX server:Network security: LAN Manager authentication level = Send NTLMv2 responses onlyNetwork security: Mininum session security for NTLM SSP Based (both on the client and server) = No minimum (from 128-bit default)Network security: Restrict NTLM: Add remote server exceptions for NTLM authentication = I input the domain IP addresses and server nameNetwork security: Restrict NTLM: Add server exceptions in this domain = I input the domain IP addresses and server name
The only other system changes I made were dropping the User Account Control Settings to the second to the lowest setting (Notify me only when programs try to make changes to my computer...) because the constant pop ups are annoying. I also set the network user login as an administrator on their local computers when I set up their accounts on their computers.A few different scenarios play out:

1. When one of my employees is trying to access a network file (excel), she is unable to. The program will launch, but the file cannot be opened from her workstation. IN the lower right hand corner of the Excel window I will see the progress bar move, then it does nothing. The program will hang and has to be force closed. This file is on a shared drive on a Win2003 server (completely open to all domain users.)

2. When trying to save an IE9 file, the user is not able to change their target location, and when they do, it freezes IE9.

3. When trying to attach a file to an e-mail, the users are not able to browse their computers to find the files they want to attach.