For some reason my character will just stop running randomly. Usually only when I am inside dungeons or houses. Always run is switched on, and if I use the map to walk around she will still run. But just clicking to move makes her walk incredibly slow, is there any way to fix this?

Check to make sure your Num Lock is also on. If it is off, the game seems to revert back to walking, despite the setting being Running: Always On.

This is what I discovered.

Oh dear, this is embarrassing. Turns out I was just encumbered and didn't notice.

Yep, that'll do it, too!

Glad you figured it out. :)