yellowTab just announced that they're experiencing problems with Paypal, affecting their ability to receive customer orders. Here's what they said:
To all our customers,

we are currently experiencing difficulties with PayPal. Unfortunately this also affects our web shop. We are working with PayPal to resolve this problem but should you experience difficulties placing an order then please accept our apologies and send the order by e-mail instead to Torsten Linde (This email address is being protected from spambots. You need JavaScript enabled to view it.) who will personally take care of your order.

Yours faithfully

Torsten Linde CEO yellowTab
So if you've been having problems placing your order, now you have an alternative while this situation isn't resolved.