AbdulAlhazred
Legend
You mean searching for something as a minor means I can search only in one square? Thanks
Sorry, that is actually not substantiated by the RC's descriptions of the Stealth and Perception Skills. Actually the RC is a bit fuzzy in some respects, as it describes an action called 'Find A Hidden Creature', which is described as simply a minor action to do what it says, with the DC being the Stealth check result. This presumably is a way to get a NEW ACTIVE Perception check against the creature's pre-existing Stealth check. If the creature is invisible (as in this case apparently) then it REMAINS SO, but its location becomes known. Again, the Stealth skill rules do make it plain that even an invisible creature must still become hidden using a Stealth check or else other creatures will know its location (but still target it at -5 with single-target attacks, as it remains unseen).
How this interacts with the power in question is still obviously a mystery. The power implies that a character becomes hidden WITHOUT any Stealth check. Does this mean they effectively have a Stealth check value of INFINITY??!!! We don't know! The power literally isn't written in a way that matches with the processing of Stealth and invisibility in 4e. Whomever wrote/edited it clearly wasn't well-informed about this part of the rules!
IMHO the power should grant an immediate automatic Stealth check with a large bonus, plus invisibility. That would cleanly solve the problem. A keen enough Perception would be capable of identifying the location of the user, though if you were handing out say a +10 Stealth power bonus that would be a pretty tough trick! In any case, even the ordinary Stealth rules state that you can't be hidden from a creature which enters your own space, playing 'minesweeper' always works, even against invisible opponents, and the power actually weakens that a bit by revealing you to adjacent opponents too.
Truthfully, for most purposes, you can simply assume all monsters fail all Perception checks to find the target. Its not going to matter much.