First: Delete your aud.ini fileC:\Users\Your Name\AppData\Roaming\Cakewalk\SONAR Platinum\aud.ini
SONAR will "rebuild" the aud file.
Then start "troubleshooting" if you have any issues.
You have the latest drivers from RME? Win 1098, although any "recent" driver should work fine.
What else is on the USB root hub?
I keep the interfaces (Babyface in the office, UFX in the studio) on a root hub by themselves.
Device Manager > USB Bus Controllers
Somethin' ain't right if Snap, Crackle and Pop are haunting you at 2048.
HTH,
T