If you don't want to do this -> :banghead: (or keep it to a minimum), then it might be best to just buy a mac. Building a Hackintosh isn't always a breeze so you'll occasionally run in to issues throughout the life of your machine.
I would take a look at some of the builds that have used...
There might be a backup that was created or it may have unfortunately been overwritten. Check the default theme folder and make sure it's the one that you wanted. Worst case is that you have to redownload the theme and place it as the default theme.
Did you read the KB article? Did you read the comments above? My guess is that 5,1 is considered a server and server host computers are unable to support any OS other than Leopard and Snow Leopard per the KB article.