Wrong filesize when capturing with WinDVR!

[Satanico Pandemonium]

I use InterVideo WinDVR 2.0 for capturing...and btw, it producess very good results even at hi-res!
The problem i notice today after hours and hours of test capturing and configuring...
The program was set to capture at 4300 Kbps. And the final mpeg file has reasonable size. For example, i captured today 1h 35min 16sec of video which came out as 3,11 GB mpeg.
BUT, when I loaded this file into TMPG for editing(i wanted to cut commercials out) edited file was about 11 GB!!!
I loaded original file again into TMPGenc to check bitrate of it...and it says 9799kbps!
Same happens when i load into any other editing program.

[Satanico Pandemonium]

Anyone?