It is very difficult if you have a problem at sign up at Google adsense.Usually Google adsense creates the account to the sites that fulfill the Google adsense policy.So signing up is not that hard at adsense.But if once your account is disabled,it is difficult for you to create an account as google doesnot allow to use same email address and blog URL while you sign up.So I have one trick to make easy adsense account.
Make a new adsense account
First is you need to make a new Gmail account so that you can use Google knol.Through Google knol,you can make a new adsense account.
When you make a new gmail account then,sign in for knol and start using it.It is like writing an article.
Then write a knol,i.e an article at Google knol and to display ads,Goto preferences and select adsense and from here you can create a new adsense account and thus can use same account at any other website.