TMPGEnc Video Mastering Works 7 is very SLOW

I'm currently trying out When I imported a video file to TMPGEnc Video Mastering Works 7.
I'm a great fan of this company, they produce excellent, stable and reliable products.
Unfortunately i"m experiencing difficulty in using this software, when it comes to locating specific points on the timeline of the imported video.
I found it very difficult to navigate to a specific point in the video clip as it scrubbed the timeline very slow and jerky.
Exporting the selected portion as a new MPG file is really fast and great.

I'm not having this issue with other video editing software that I am currently using.

I'll feed this information back to Pegasys and see what response I get from them.