Like was already mentioned by TR in that other thread, if your mast is still raked like it looks to be in your picture, the boat is never going to point upwind. Did you address this at all? I dont know how it should be set, but it looks WAY too far forward and that wants to drive the boat downwind. My .02, spend your time getting the sail plan balanced correctly first, then learn the tricks for best going upwind.
A manual that might be close is available on this site (thanks to whomever spent the time to set this up)
http://macgregor.sailboatowners.com/images/kb/pdf/1361.pdf I didnt read this but it may have some info on how to set the mast rake correctly.
edit.. I looked at that link, looks like no info on correct mast rake