MMC keeps crashing when attempting to save a WMI

Hi all.

Everytime I attempt to save a WMI I get the following:

I then click on 'Debug' and get this:

So basically I can't do anything!

This is what I find in the Application logs (Event id = 1000):

Faulting application name: mmc.exe, version: 6.1.7600.16385, time stamp: 0x4a5bc808
Faulting module name: OLEAUT32.dll, version: 6.1.7601.17676, time stamp: 0x4e587ee8
Exception code: 0xc0000005
Fault offset: 0x000000000000984a
Faulting process id: 0x%9
Faulting application start time: 0x%10
Faulting application path: %11
Faulting module path: %12
Report Id: %13

Any help greatly appreciated! :-)