"If you need help upgrading your blog let me know, there are no unsolvable issues with regards to plugins or themes and new versions of WP. Unfortunately on the other side if your blog has been compromised things get infinitely harder and you really need your web host or someone savvy with systems to clean up the damage. Even if you fix WP there's no guarantee they didn't leave a backdoor somewhere else in your account and you need to diligently check for that. (Like if you get spyware on your computer.)" - Matt Mullenweg