Windows Movie Maker Freezing Up

Hello to the forum:

Hope I can go into a bit of detail.

I have a Gateway 700XL System P4-3.00, 250 GB 1024 Memory MB. Windows XP Norton Anti Virus/Norton Internet Security 2003 and Windows Firewall all are enabled.

Windows Movie Maker came with the system and I purchased at time of install Pinnacle TV/Video Tuner that lets me watch television, watch the VCR hooked up to the system and record from the VCR.

If I want to edit let's say a downloaded clip of a baseball highlight it is usually fine in Movie Maker. If I want to edit in Windows Movie Maker or even any freeware Video editing Program something that was recorded on my VCR into Pinnacle and saved on the hard-drive the clip will usually be frozen for 2-8 seconds before it wants to play and lets me edit. Video Card is Radeon Ati 350 9800 Pro 128NB.

No other program is open, I am the only user and I run a Virus Scan every 2 hours and a Spyware Scan every hour since I have had the computer. I constantly delete all temp files/history and only audio songs are saved on the hard drive (using 8 percent of the total space).

Why is a recording through Pinnacle so upsetting to any of the editing programs and what would be your recommendation based on the info above? Everything is saved as an MPEG file.

Thank you all for your time and have a great day.