I believe they are trying to charge people for the latest version via donations
I would guess that if there is a 1.7 version available to free forum members then it's an older build
A bit of googliing might score you a free copy, they are calling it donations so they are not considered selling it

so I would not consider that illegally obtaining it
There is also a last build by Jabo who is no longer an active part of the PJ64 team released September 13th, 2011
http://jabosoft.com/articles/115
thats called PJ64 1.6.1 and was released after the last 1.7 build I had
P.S. if someone want to upload a save file (not a save state) then if I get time I could check it out for you
Just tell me what to do from your save to get to the crashy/unstable bits and see if I can't figure a way round those