I have a 98 Impreza. A little while back it started popping out of 4th while driving thrn 3rd and 5th followed.  First question what would cause this? Second question I was going to take it to my mechanic to get the transmission checked. It backed out fine went into first fine, but when I tried to go in second it would not go in gear and would not go into any gear after that.  What would cause that?  I am mechanically retarded, the second sounds like a clutch issue, but I'm lost on the first issue.  The car only has about 135k miles on it.  Any info would be greatly appreciated