The warlock’s deceive item class feature (Complete
Arcane, page 8) allows him to take 10 on Use Magic Device
checks “even if distracted or threatened,” but the Use
Magic Device skill says you can’t ever take 10, regardless of
distraction. Does deceive item also let the warlock ignore
this restriction?
This class feature really does two things. First, it allows the
warlock to take 10 on Use Magic Device skill checks (a boon
all by itself). Second, it allows him to take 10 on such checks
even in conditions where that would normally not be possible.
根据这条FAQ的精神,Skill Mastery应该可以让UMD T10(Warlock那个能力的规则描述和Skill Mastery是一样的,而且也没规定Skill Mastery不对UMD起作用)