In his original post he stated: "Also, there seems to be something in the middle of 5th and reverse. I can get in reverse, I just can't go straight down from 5th. Could this possibly be a loose cable or like a bushing?"
My response was for that question. As a tranny popping out of third or fifth gear is OBVIOUSLY a problem. Read everything before you go around insulting people. And syncros have nothing to do with popping out of gear if you are already in gear. Bad syncros would make it unable to get into gear without severe grinding unless you match rpm perfectly, but he said nothing about grinding.

tonyredshoes: If your tranny just started to pop out of both third and fifth gear recently then it is likely to be your linkage. Shifting into third or fifth gear pulls the same connector back. If this is the case first gear might start popping out soon too as it uses that connector also. I very much doubt the dogteeth on both third and fifth gear went bad in this small on a time frame.