Ah I see. It still baffles me how you thought of all the functions. I mean, it was a lot of work just implementing them all in my GUI, which was practically the same for every function, but compared to actually thinking of and implementing these it's nothing. One can't stress enough how great your work (and the work of all the non-profit freeware developers out there) is.
Btw: I released the new version on my website. Unfortunatly it's not possible to update with the auto-updater in my program because of a bug in the updater (and I didn't implement a way to update the updater first..). But you can just download the new version at my website.
It has the multi-core feature in it. There is sometimes a little problem with djvu files because the number of pages is not read correctly (don't know why) but this is a rare case. The conversion still works anyways just the load on the different processes is not distributed evenly in these cases.