Conversion to pdf not working

This is driving me crazy - I cannot seem to be able to convert files to pdf with decent results...

I want to convert a .mobi file to pdf, so I can read it on my iPad with my favorite pdf annotation software (I'm aware I can read .mobi on the iPad, but for reading on the iPad i prefer pdf). However, I cannot for the life of me seem to convert the .mobi file to a decent pdf file. The file which comes out is all screwed up, with the text barely visible. Here is an example of the kind of file which comes out of the conversion:

http://www.box.com/shared/441c44cfdfec1fd16146

I've set 'input profile' to 'mobipocket' and 'output profile' to ipad. I played around with different input and output profiles, but nothing fixed the problem.

I'm using version 0.8.41 on the mac. This has been faulty for a while; I upgraded several times to the new version of Calibre, but it was never fixed. I recently tried to convert a .txt file to pdf, but that didn't work either.

Anyone have any ideas? I would be terribly happy if I got this to work...