My mrs has started having troubles with her 2002 red tdi lupo. The car will select all gears without the engine on 1.2.3.4.5. and back down fine 5.4.3.2.1. When its started up, its the same.... When driving she can select all the gears upwards ok, but coming back down from 4th to 3rd, the gearstick wont engage the gear, its like it hits a solid wall.. No crunching in or anything, just a solid block.. To get 3rd from 4th we have to go 4-2-3 to get it in... The lupo had replacment gear selector cables a while back as the old one had apparently snapped, so we were thinking it could possibly be this... But then again it does seem to select fine other than coming down from 4th to 3rd. The only other things i can think is oil, or sync in the box... But being a TDI the gearboxes are quite expensive. Can anyone shed some light on what it might be? The clutch and pedal box are A-OK, and reverse is also fine...