AGCH congestion with TRAU failures

Hi,
We are experiencing AGCH on cells looking in very high traffic carrying regions. TRAU failure are also appearing on the same intervals, could they both be related and what else could be the reason for TRAU failures.
Also could any degradation result from having more AGCH reserved on one cell then other cells of same LAC and BSC. hopefully paging que shoud hold on to access paging requests and accomodate, and if the paging que starts to expire we should get paging overload alarms. Right?