Experiences vary depending on what browser you're using. I use Chrome and have had no problems with the forums or the store in quite a while, but I know there have been some people that have had issues using IE. 

You can post any problems you're having to the Marketplace Customer Service forum and make them aware of it if they aren't already. Or the Community Center forum for more general issues not specific to the store. Just be sure to give as much detail as possible - which browser, etc. Admin are usually pretty quick at looking into specific issues when brought to their attention.