I recently bought ToonBoom after using the trial for 20 days. I never had any issues during the trial, but now I am having a delay between when I draw and when the line shows up. This only seems apparent when onion skinning is turned on. Maybe this is some strange setting.
For example check out this screen capture: http://youtu.be/8mNQi5vAx5M
Using a Wacom Tablet, Mac Pro, Tons of video card and processing.
Onion skinning is a transparency effect and these require more resources for your graphic card to process. You say that you have “Tons of video card” but what specifically is your graphic card model? Which version of Mac or Windows?
If you’re on Windows 7 or Vista, try disabling the Arero Desktop theme by right-clicking the desktop, selecting “Personalize” and scrolling to the bottom to select one of the Basic & High-Contrast themes instead.