MitsuStyle - Transmission Problem, need help fixing

1991 Eagle Talon TSi AWD 5spd
Relavent Mods: Southbend Clutch and custom street disc (Ross's old car)
Transmission is rebuilt with less than 4000 miles on it.

I've been having problems with 5th gear on my tranny. When I put it in 5th gear and give it some gas, it comes out almost all the way, but stays in and still drives, but it grinds for a second until im going a little faster. Then, when I let off the gas, it pops out entirely. I had trouble with this 2 weeks ago, and then it went away after 2 days, so I just thought something must have been frozen or something, so I let it go, even though there was some light grinding (probably a bad idea). So for now, at least I can get to anywhere I need to where I live without going on the highway. Anyway, I searched v-faq and figured out what the problem is if it isn't my shift forks going bad.

http://www.geocities.com/qwik93awd/Vfaq/shifter.htm

I was wondering if anyone had some free time to come help me out on this that knows a little bit more on transmissions that I do, or is more experienced on doing work like this on a car. I can offer some cash and a case of beer:D! Anyone available to help a guy out Friday afternoon or Saturday? Otherwise, I'll have to take it in and this will be a lot cheaper to do at home than have a shop fix it. Any help or input is greatly appreciated!

Tom