Problem storing ACL in registry

Hi,
I doubt this problem specifically relates to the ACL, or the
registry, 
but when I try to add my ACL (which is only small; only
contains 10 or 
so rules) to the registry I get the "Allowed memory
size of 16777216 
bytes exhausted" error. I tried to increase the memory
size to 32mb, and 
now I get "Maximum execution time of 30 seconds
exceeded". With both 
settings the request takes quite a while to return the
error, so I think 
something else is wrong, rather than just too much data.

Any ideas?
-- 
Jack