Wow guys, didn't expect this to resolve this quickly. Thank you very much!

I'm sorry, I'm kinda new to this whole thing: so this means the PPLNS was actually right? I thought this was somehow dependent on the frequency a pool hits a block, e.g. pool hits a block every 2 hours --> PPLNS window is maybe 15 minutes; pool hits a block every 2 weeks --> PPLNS is around 2 days (or something like this...).

Anyway, the payment arrived (not sure if you were able to somehow reproduce my contribution or just averaged it, but it should be about right^^).

As soon as I get my miner going again, I will continue XMR here. Let's hope this pool quickly gains attention and users! :)

P.S.: my XMR address: 42M77R2MbvmZXvogyPBVjcJYXrJ7GUFz7aDxFPbbpiYn17hVwCVDVDtJaB3bNLL5YoWjMQvUmXFvaQZqSfFkhxgAHRMxVmb