Unfortunately from Spring 2012, Salesforce has disabled allowing Person Accounts to have access to Partner/Customer Portal or Communities 🙁
See the note here under Self-Service Portal:
https://help.salesforce.com/HTViewHelpDoc?id=account_person_behavior.htm&language=en_US
Or this:
https://help.salesforce.com/HTViewHelpDoc?id=networks_create_external_users.htm
“Keep in mind that if your organization has person accounts, they can’t be used as partner accounts and you can’t create partner users that are associated with them. Only business accounts can be used as partner accounts.” purchase college papers