My account says
Payments 107.3 €
Used 82.75 €
Available 24.55 €

My GWP says
4704 positive points
GWP
Available for paid downloads
Paid: 10730
Used: 8275
Available:

Detailed payments overview
Donations
Do you want to donate money? 2000
Loyalty bonus 163
Visits/Logins 14
Decodings 16
Comments about file quality 9
Affiliate 0
Other 47

1 € = 100 GWP

You can see all your payments in the positive GWP area. If you use these payments to get a paid download, your negative GWP for 'used for paid downloads' will be increased.
365 negative points
GWP
Traffic 148
Used for prio downloads 217

But when I go to down load under

Bezahlter Download von Ihrem Konto
it says

Ihr Guthaben ist zu gering. Sie können es hier aufladen

Why would that be?