That sounds like a linkage problem. 2nd 4th and reverse are all on different synchros (well no synchro for reverse) but its all in the shifter pull. Inspect the linkages on the trans and the bracket there as well. Also check the shifter area there are adjustments that can be made to the cable. There is also the possiblity of a broken cable
Could be , I never liked the cable set up on those cars...but then again, it is a DSM...