PHP site broken, need to move to Linux Server - GoDaddy!

I have a php site ([login to view URL]) hosted on GoDaddy - We are having multiple problems with the site since we moved it from another host a few months ago. It is sharing a Windows hosted account and I think it needs to be moved to a Linux Server. We have a Linux Server Hosting account already with GoDaddy but need to move this site. The database will also need to be moved. The other issues we are having that need to be fixed: images are not uploading properly, we are not able to edit photo galleries, we REALLY need to be able to upload sponsor logos and some flash ads and we haven't been able to. I need the site moved and all of these things fixed. This site is pretty dynamic and has a custom CMS - it needs to all be moved and fixed seamlessly with very little down time - sponsors are waiting!