Don't throw it ! You'll regret Do you have the possibility to try a (desktop) PC? You already tried a different laptop and it caused exactly the same problem right? Did you make use of an external power supply for the UMCP2? Try that.
Of course it could be the controller which is defect in some way. You never know ..
Hallelujah! Problem seems to be solved: after un-installing all of Cross DJ, updating all Windows systems ans finaly starting Cross DJ under Aministrator Rights - the thing got working!!!
I already got a taste of it without Admin rights but after about 10 min. the U-Mix went offline again and there was no way to get it back online except rebooting the laptop. When I run Cross DJ as Admin it seems to run stable and remains online. I did not try it out yet in a gig but I was testing it last weekend for several hours without any problems. So I have my hopes high that it will also keep up when I really depend on it during a gig.
So for now I would say: problem solved! Thanks to everyone who posted tips & tricks!!!! :-)
had issues early on and restarting /loging off and restarting Cross under admin rights and turning on u m c p gets it to come on line,,,argivating but it gets the job done
January 2012 Mixvibes DJ of the month MEMBER OF: C00l People MV Society
2014 dell XPS8700 intel core i5 4400@3.10ghz 12 gigs DDR3 ram NVDIA GeForce GT635 Win 10 /64 bits OS Realteck 7.1 Home USB sound dogle Asus VE247H monitor Logitec G-15 ser 1 gaming keyboard U-Mix Control Pro 2
You'll regret 
do me a favor ,,restart your computer and boot up Cross under admin rights ,while Cross is booting up turn on the control pro , 
