I went to preferences in the main dialog and changed the order PM reads xml and IPTC files because changes I was making in Lightroom were not showing up so I switched it to XML then IPTC. On pressing the OK button to confirm, I got the spinning beachball and after 5 minutes of unresponsiveness I force quit PM.
I just seem to be getting intermittent periods of unresponsiveness that seem uncharacteristic of a program which comes so highly recommended from so many people.
Once I re-opened PM I did indeed try your suggestion of telling it not to hunt for sub folders when browsing the navigator and that fixed the previous problem I was having. Instead of taking 5 minutes+ to expand my folder tree it was suddenly instant ( though of course now lost ability to see when there is a sub folder). It seems like a workaround, and I've never experienced any program before , let alone one that is fairly expensive, where simply expanding a folder tree can take 5 minutes regardless of whether the folders are on an external drive.
And a simple sort to find the files tagged with a specific color is still taking upwards of 5 or 6 minutes.
EDIT: In fact as I sit here now trying again to perform that same task to simply show me only files tagged red, it's now been spinning the ball for ten minutes. This can't be normal behavior is it ? I no longer know when it's crashed or when it's just doing something very slowly.