User123,
It is a known problem with mlock on UltimateIRCd series, both 2.8.x and 3.x.x
It has been pointed out for the developement team more than once, but they seem not to care about fixing it. So you're not alone with that problem. You can always try to post your problem on their forums, if not already done, or change your IRCd to another one.
Anyway, it's not related to Anope Services, but IRCd related, since all mlocks work for me since I changed IRCd and still using Anope Services.
[Edited on 18-10-2006 by Alex]