Crimson wrong native monitor resolution

I'm using the latest Crimson 17.1.2 and got the problem, that i am not able to switch to the native monitor resolution from 2560x1440, as it not shows up in the list of the screen resolution setting. I tried to create a custom resolution but the software says, that this is not supported.The monitor is a newly bought Iiyama ProLite B2783QSU connected via Dual Link DVI with a native resolution of 2560x1440 and this is also reported from CRU - Windows driver for the monitor is also installed and includes 2560x1440 as max resolution...

So why does Crimson not check it??

 

2017-02-01_20h52_21.png

 

Any ideas?