This can happen if the Capture Layered Windows option is enabled in Recorder's Tools > Options > Capture dialog. Disabling this option will resolve the flickering, however some types of windows and/or tooltips will not be captured in your recording as a result.
The flickering cursor does not appear in the recording, so we recommend enabling the Capture Layered Windows option to ensure the capture is accurate.
Captured layered windows is on by default in the PPT addin but can be turned off by clicking on Camtasia Studio Recording Options within the Camtasia Toolbar in PowerPoint. The flickering should not appear in the finished recording.
One last step to try would be to update your video card drivers from your computer manufacturer's web site.