Just discovered to my joy why calibre has been hanging on clicking Convert Books. I use CCleaner on a regular basis and after un-checking clean Temp Files the hang-up doesn't happen. I've browsed some folder locations and found some files starting with cal, among others. Although not cleaning the temp files stops the problem, I don't want to have the temp files folders bulging with megabytes over time, so which files need to be left in place to stop the hang-up on conversion?
Any comments much appreciated.
