I am having the exact same problem. It started with the upgrade from (K)Ubuntu 14.04 to 14.10. VMware Player 6 used to work perfectly, since the upgrade I have been experiencing high CPU usage whenever I try to switch between KDE and the virtual machine, among other things. Upgrading to VMware Player 7 did not solve the problem.
Could you make any progress on isolating the cause of the problem?
