I noticed this exact problem with the ‘enter’ key not working in some forums and some websites. It only happens with IE 10 and not the earlier 8 or 9 versions. I sent a message on a Microsoft forum but never heard a response to that issue. For something like the ‘enter’ key not working it seems more like IE10 is still a beta version and not ready for prime time. I also would recommend Chrome or Opera.
Yes. IE10 is buggy with Win7. I immediately uninstalled it last week after similar problems with my email.