OK. Back up and running on PM 1.85.490.0 and I've continued with my custom package to deploy the mms.cfg file. The deployment is working but it keeps deploying. I check the WindowsUpdate.log and can see this error.
WARNING: Failed to evaluate Installed rule, updateId = {F530906C-E1A3-424F-8796-A9C7941184D2}.1, hr = 80070002
The fact that it's failing to evaluate the rule appears to be the reason why the deployment keeps occuring. So I tried a few variations of the Installed rule but with no success. Here's my Installed rule.
File Exists: Path=C:\Windows\System32\Macromed\Flash\mms.cfg Common Path=NONE Version= Size=N/A Modified Date=20/02/2013 11:29:02 AM Creation Date=N/A Language=Language Neutral.
The Date Modified according to Windows file properties is Wednesday, 20 February 2013, 11:29:02 AM. So my assumption is that this patch should find the file, see that the modified date is as expected when installed and therefore flag as already installed.
Any help appreciated.