Shift Lever Problem

Here's a problem that just started w/ my '98 OBW w/103,000 mi and 5spd manual transmission:

In the past, when the shift lever was in the neutral position, there was slight resistance to either move to the left near 1st and 2nd or to the right near 5th and reverse. This was normal and appropriate.

Now, there is resistance when moving the shift lever to the right, but no resistance when moving it to the left. In other words, the shift lever will flop over to the left with virtually no effort.

This is making it hard to find gears when shifting up from 3rd to 4th or down from 5th to 4th.

I have removed the shift boot, and looking down from inside the car everything looks normal.

Could the rubber bushing in the shift linkage under the car be the cause of this problem? Any other ideas? I would appreciate any help you can give me.