It could be the synchros or a bad shift cable, but usually the shift cable would be noticable in several gears, like 1st-3rd-5th or 2nd-4th-reverse. Considering your description of the symptoms I would lean more toward a dead synchro. It won't cause the gears to pop out while driving but it is usually very annoying. I drove a car with a dead 1st synchro for 50k and it never got any worse

You could have the trans rebuilt, replaced, or just live with it

Erik P.
Official 2GNT thread Hijacker
Some say that he's driven over more Covenant than he's shot, and that his grenades aren't where you'd expect them to be...
All we know is, He's not The Stig... But he is The Stig's Spartan cousin!