LSL bug? LinksetAlpha not working with control perms

Hello. This is a little section of a script I have. This goes in the listen part.

if(llToLower(message) == "start"
{
llRequestPermissions(llGetOwner(),PERMISSION_TRIGGER_ANIMATION | PERMISSION_TAKE_CONTROLS);
llStartAnimation("start anim";
llOwnerSay("Start message.";
integer1 = FALSE;
integer2 = TRUE;
}

Changed the names of things from the original, to keep them to myself. Anyway. This works correctly, and is used in a melee weapons script, so the controls would animate the avatar in various ways. Weird thing is, when I add llSetLinkAlpha(LINK_SET,1,ALL_SIDES);, anywhere in this listen, Controls are simply not set, and the script stops listening on channel 0. I remove the alpha part and it's back to normal. I even tried using llMessageLinked and making a separate script with only the alpha message, in another prim of the object. But even that failed. Old scripts I have that have alpha settings, seem not affected by this. But any new script I make has this problem. Anybody has any info on this?

I expect it's somewhere else in the code... Can you post some more code?

I run llSetLinkAlpha(LINK_SET, 1.0, ALL_SIDES); in all of my weapon scripts and it works just fine. The error is definitely somewhere else in the code.