那麼我不知道是什麼原因導致錯誤不允許您重新提交付款. System hung up on old card no.

Once you switched to Paypal, the "old memory" on the wrong card number was erased.  Then it allowed you to resubmit CC payment. 

Lately I found my Gmail also acts crazily - it would just keep loading and loading but would not open an email.  I have to navigate to another tab then return, then it would work normally.  Or a page refresh also does the trick.  Annoying to say the least.