Make sure that both requested amounts are in the same currency. (Sometimes this is not readily visible)
For instance, I am Canadian, but when I buy an item from a US site (Amazon.com rather than Amazon.ca for instance) they both use the $, and do not say CAD$ or US$. However, upon cash out, the charge is 30 cents on the dollar higher due to the currency exchange. So when purchasing something, make sure you are cashing out in the right version of currency or at least accounting for the conversion.
Also note, some of the finances may be locked due to security issues. New customers sometimes experience hold on funds for various reasons. Check to see if your subscriptions are due. Check recent purchases to see if there is any pending purchases.
Just remembering some of the issues I have experienced. There are others, but a sure fire way to find out why, would be to contact PayPal support directly.
PalPal support
