There are several problems that you can have with the shifter in the 90-99 model DSM transmissions.  I'm not going to re-invent the wheel for this one being that Tom Stangl did a fine job explaining this stuff many years ago.

For all the shifter related into that you could possibly ask for (and more) please check here:

 http://www.vfaq.com

http://www.dsmtuners.com/forums/drivetrain-tech/93739-90-shift-linkage-vs-91-94-shift-linkage.html

http://www.dsmtuners.com/forums/drivetrain-tech/355940-how-shifter-cable-brackets-diff-between-90-91-dsm-vr4-trans.html

Also make sure to read this page.