I'm new in this forum.
On seeng the phrase in one of the posts here on this forum I almost instinctivly knew that it should have been new to this forum or to a lesser extend new on this forum, but having googled each one of the three variants up, with quotation marks, I got a bit baffled by the fact that all three had fair amount of hits, to this forum being a leader. Does that mean then there's nothing wrong with I'm new in this forum sentence?