I had written about the TokenPerm cache store in a previous blog post of mine. The trace flags mentioned in the KB Articles helped in throttling the cache to prevent the cache size from growing out-of-proportions. Recently, a new Trace Flag (-T4621) was added SQL Server 2005 Service Pack 3 (KB959823) to customize the size of the Token Perm cache. Instead of hard coding the quota for Token Perm with the earlier trace flags, you can use the formula to specify the Registry value:
Quota = 1,024 * 2 * ( <Number of Distinct Logins> + <Total Number of Users in each database> )
Remember to turn off the other trace flags for Token Perm issues that you had activated on your systems previously. You cannot enable trace flag 4621 together with trace flag 4618. When trace flag 4621 and trace flag 4618 are enabled together, trace flag 4618 takes precedence. The reason this trace flag was introduced was to prevent detrimental effect to systems where constant flushing of the Token Perm cache would affect the performance rather than helping it.