You won't see the arrow if you have the debuff if you are targeted with ice lance I believe. If you have ANY debuffs when tombs are coming out, just make sure to be safe and stack anyway Edit: just did it tonight, seems they fixed this problem
Last edited by Squishychunk; 2012-01-11 at 04:24 AM.
I've had this problem as well (the marker randomly not showing up sometimes). Worst part about it is, is that it gives anyone in the raid an uncheckable excuse if they fail -_-