PayPal doesn't add single payments in, but subscriptions work just fine

Hello,

As you can read from the title, I'm experiencing a very awkward problem with PayPal. I've had this problem for quite a while now, and I don't understand what's causing it. I've been in contact with PayPal, but they're not too helpful with the matter.

Subscriptions add in just fine, normally, but normal payments doesn't even reach my server it seems like. I have checked every log there is, and I can not find it.

Any ideas?