I bet they also levelled up their health* at every opportunity rather than their stamina, meaning they couldn't carry much more than a couple of loads of coal at any one time.
* - Has to be health as I don't remember many magic-using miners
Definitely made a difference, which is nice. I still have to run the game windowed to stop the ATI graphics card stuttering problem. Not a problem though.
Also fixed a quest I had a problem with so I can find the word wall it was supposed to be directing me to now.