My 1999 C4 6 speed just started to slip out of 1st gear when I start (as i realase the cluth). If I dont hold the stick, it will actually pop out into neutral, and grind as it does so. Once I am moving I have no prooblems, and I have no problems in any other gear.

Any thoughts?

Thx

 

Some cars will do this on cold start ups. Once the fuild is warm no more issues. If that is the case you might try a fluid change. Ie drain and refill with new fluid.
Gbox makes a part that help with 2nd gear pop out. Not sure if it will help with 1st. Call them and I am sure they can help.
Last would be the gear synchros. This would required deeper pockets.