You could try and follow my instructions on my blog for installing to a subfolder although I haven't retested with the latest version of YAF; it did work with 1.93 no problems.
(See blog link).
"It's a case of RTFM.. the only problem being we don't have a manual!"
When I post FP:Mek in a topic, I'm leaving my footprint there so I can track it once I get into coding/supporting. (Yes I stole this off Ederon 🙂 )
Thanks for all your help