Could be a couple of things
1. Just noticed you say its vertex animation, use bones instead, vertex animation works in FPSC but it requires additional method.
2. You may have the animation numbered correctly but you also need to know that anim1, requires that you have animmax =2 in the fpe.
;animationinfo
animmax = 2
anim0 = 0,100
anim1 = 0,100
3.I use sampled and matrix in export settings for boned animations, optimise mesh-none, animation options-closed.
4. Try the following script instead its the one I use to test all my anims.
;Artificial Intelligence Script
;Header
desc = Animate object
;Triggers
:state=0:setframe=1,state=1,incframe=1
:state=1,frameatend=1:state=0
;End of Script
I don't trip over...I do random gravity checks.