Thank you, thank you, thank you bpiphany!

That was my first soldering experience and what a fun it was! My first electronics experience even!
Anyway, finally I have finished soldering my first Frosty Flake. It was not perfect, I had to resolder few things a few times, but now all keys are go!
I still have one problem though and I have no idea where the bug could be. All leds are always on.

I have red leds, and I have used 510Ω resistors. I've inspected original CM QFR and it also has 510Ω. Again, all keys work; Caps Lock functions fine, the led just stays on regardless. I read 3.3V on the led pins. I've probed all resistors on the Flake and they show the right values. Being a total electronics nub, I just don't know where to look further. Any advice?