Some Zeds do it, for a variety of reasons.
On rare occasions it's quite normal - the car is stationary and the splines don't mesh.
If it does it also with the engine off, it might be gear linkage, external to the gearbox.
If it's only with the engine running, the culprit may be the clutch on its way out (it does not disengage fully).
It also can be, as in my Zed, a tired 1st gear synchro (internal). I've had my gearbox dropped, gear linkage checked, clutch and flywheel replaced (I had audible flywheel chatter) - so we ended up with the synchro. It does not bother me much as I can do the 2-1 flick, it's temperature-dependent, and can be remedied by running a thinner gearbox oil.
Anyway, a proper diagnosis requires dropping the 'box and checking.
