[MP2]

It's a GTA issue. You have to pre-load the animtion library to apply animations from it. One solution is to, as Drebin stated, apply animations twice. You could make a custom function for this for ease:

pawn Code:

stock ApplyPlayerAnimation(playerid, animlib[], animname[], Float:fDelta, loop, lockx, locky, freeze, time, forcesync = 0)
{
    ApplyAnimation(playerid, animlib, "null", fDelta, loop, lockx, locky, freeze, time, forcesync); // Pre-load animation library
    return ApplyAnimation(playerid, animlib, animname, fDelta, loop, lockx, locky, freeze, time, forcesync);
}

Use ApplyPlayerAnimation instead of ApplyAnimation. [not tested.]