I had a very similar problem. Every time I moved my mouse over a button or icon, it could (not consistently, seems a bit random) take about 2-4 seconds before the button would highlight. Clicking an action, or even pressing spacebar to play/pause also has the lag. In fact, everything in Cakewalk would lag.
I managed to fix it so it has no more lag from some of the replies - basically to turn on Graphics HW Acceleration.
1) Run Registry Editor.
2) Go to Computer\HKEY_CURRENT_USER\SOFTWARE\Cakewalk Music Software\Cakewalk\Core
3) Double Click on UseGraphicsHWAccel.
4) Set Value data to 1. (If it is already 1, then this is not your problem I'm afraid).
5) Close Registry Editor, and test Cakewalk. Hopefully it is fixed.
