[denNorske]

It sounds very much as a virtual world problem to me.

Have you tried hooking the "SetPlayerVirtualWorld" with _ALS_ and then tried to print each time it's called?
This way you can see if you actually change virtual world or not, and continue from there

Example

PHP код:

stock realSetPlayerVirtualWorld(playerid, virtual);
{
    new str[80];
    format(str, sizeof(str), "Your World changed to: %d", virtual);
    SendClientMessage(playerid, -1, str );
    SetPlayerVirtualWorld(playerid, virtual);
    return 1;
}
#if defined _ALS_SetPlayerVirtualWorld
    #undef SetPlayerVirtualWorld
#else
    #define _ALS_SetPlayerVirtualWorld
#endif
#define SetPlayerVirtualWorld realSetPlayerVirtualWorld