i just tried to add a credit card so i can sell but it says something like 'this card is on hold by ebay, please use another card' why is this, please help?

Had you opened an account under another user name and used that card? That will cause it

Both preceeding answers are in the right direction but rather than opening another account contact paypal and ask why your card is on hold and what you should do to release it. If you have used it on another account perhaps you want to close that account and use your card on this account.
If all else fails use another card if you have one that is!

All the best.

Both preceeding answers are in the right direction but rather than opening another account contact paypal and ask why your card is on hold and what you should do to release it. If you have used it on another account perhaps you want to close that account and use your card on this account.
If all else fails use another card if you have one that is!

All the best.