Thanks heaps thekidintheclock. Worked brilliantly and I spent hours trying to find a setting in Calibre to solve the font issue with the epub's I was uploading to my Kobo reader.
I also had the comdlg.ocx error when installing the fix on XP but just followed the solution at
http://devonenote.com/2010/02/regist...x-on-x64-win7/
Very grateful :-)