Some more info would help:
- You've ensured your system is fully up to date?
- Is this after a fresh boot? (Not after the computer has hibernated)
- Is it a fresh Kubuntu install? (Have you done anything on the system yet?)
- Has it worked before on this machine? If so, what were the circumstances?
- What have you tried in order to fix it thus far?
And just to ask the painfully stereotypical tech support question: You've tried rebooting it?