Crash and Cache - ProE's secret settings

This week we had a couple of instances of ProE crashing immediately on open...
Looking at the PTC/USER exploders it seemed it may be related to PTC.com being down... not so, our config.pro has included this setting for the past 3 years:

web_enable_subscription no

(It turns off the facility to connect with PTC.com on startup)

After some time with a couple of Tech support operatives, we eventually discovered that deleting the ProE "cache" folder allowed it to start properly. This mysterious folder is located on Windows systems @

C:\Documents and Settings\%username%\Application Data\PTC\ProENGINEER

And it seems to have quite an impact on ProE... we have an inkling that one workstation perhaps got a corrupt file here during a recent power outage.

So, there's something to stick in your memory-bank for any future strange ProE crashes...