Question about Outlook Express

Hi. I would like to use Movie Maker to make simple cut - edits to files recorded with Windows 7 Media Center. I use my PC as a whole-home DVR and have a digital cable tuner with CableCard to capture digital Full-HD Shows and such. My recordings are flawless but if it try to import a recorded show into movie maker, the audio gets lagged by over a second. Playback in Media center is flawless. Playback in Media Player is also flawless. I have tried converting the file from .WTV back to DVR.ms format like prior Media Center recordings but same result. I'll get ahead of the 'your hardware is slow' crowd and say I have a smoking fast PC. Its a Core i7 - *** Email address is removed for privacy ***, 16GB ddr3, with 2 x 500GB SSD 6Gb/sec drives in RAID-0 (stripe) so I get blistering HDD access speeds. An nVidia GTS450 with 1GB dedicated vRam handles the video cards duties. I run Win7 64-Bit Ultimate (a legit purchased copy not a bootleg). All my drivers are up to date, I have all the latest windows updates. The lag remains a fixed time amount, not a gradually increaasing thing as I have seen some post who are importing from cameras. What I can see is that the audio lag gets longer depending on the file size. Since my TV recordings are full HD their sizes are large, generally in the 3-4GB area. I just want to be able to snip and cut sections I want from existing files recorded by media center. Removing commercials for example or cutting out and saving a single music video from an hour recorded from my favorite music video channel. To begin I must import the entire hour so the files are big. At first import Movie Maker says its 'converting the file for editing' or something like that and theres a progress bar at the bottom. It only takes like 3-5 minutes to convert/import the hour of HDTV but the resulting video is out of sync with the audio about 1.5seconds when you play it in Movie Makers preview pane. I have tried to go ahead and publish one of the videos to test if it re-syncs at the end but no, the resulting edited file is still outta sync with the audio. Thats very annoying but I tried to deal with it looking for a 'sound sync' feature or some audio timing editing tool to that effect within Movie Maker but alas there seems to be none. Can anyone help with this issue?