Driving along happily......... and all of a sudden i have only 1st and 2nd gear!!!

Stick just wouldnt move over to the middle (3rd and 4th) or all the way accross (5th and Reverse) so i only have 1st and 2nd!
Disconnected the selecta rod and stick moves freely, try and change gear using a small screwdriver through the shaft that sticks out the gearbox and same thing..... 1st and 2nd but nothing else, it's rock solid in any other direction and even 1st and 2nd are stiffer than they were
New box time!