It certainly looks that way from the small tests that Arve Bersvendsen has done: When is MSIE not MSIE?
It seems a lot of browsers are misrepresenting themselves as Internet Explorer. Probably because a lot of clueless javascripting on the web checks for “Internet Explorer”, and excludes other browsers.
It would be interesting to know how those kind of misrepresentations affects “official” browser statistics.
Just run into a problem of browser detection. There doesn’t seem to be any standard out there. This is a real problem. Maybe sometime soon there will be RFC dedicated to this issue since it is getting more problematic as time passes.