Mmm, ok. Umm. Well I'm not knowledgeable on the whole 'PS3.proxyserver' programs. I followed the above tutorial and it worked like a charm. I use PS3.ProxyServer GUI. I've only used it twice so far.
I've had a quick read on the other threads relating to Ps3 Proxy (these are all in the Online Chat section). Also note that their are a couple of Proxy based programs that work for certain users on these forums. PS3 Proxy by 3r1c and PS3.ProxyServer GUI by cf3b5. Try both and see if either works.
Also at what stage does the transfer error occur? If you can, detail at what step things get messed up. This way I can work it out better (maybe I'll even retrace your steps) or a Proxy 'guru' can help you, better than I.
P.S. Transfer error. Have you changed the settings on the actual PS3. Custom internet settings and 'Use a Proxy Connection' enabled. I'll explain more if needed.
With PS3.ProxyServer, 'PS3 Mode' should be ticked. You should have your PC IP address stated and Port 8080. Start should be shown. Don't forget that the full link must be pasted. Therefore:
should be shown and besides it should be the file you want to actually install.
That too will look like:
C:\Playstation 3\Metal Gear Online Beta\3JFfG1JDa78BEDTaEg9y2wkcisswFOLUX50iBRwxRpiyLcuYsGSYtpNghXrkTe1LTgUlSruMEm7JIrMhKULtSOHy2wpaY8RF8rf9E.pkg
In theory, once connected, you run back to the PS3, and click on Folding@Home, it will show 740meg (it does for MGO) and install MGO. Originally clicking on the F@H link, the PS3 would phone back home to the PSN servers and grab the F@H PKG file. Instend now it phones back to your PC and grabs whatever you have listed.
Note that you can not have F@H already installed (i think), other programs seem to work, so have a read on the forums if this is the case. Again I'm not fully 100% sure on these programs, I'm really new here. Best of luck and let us know how you go.