Windows 7 - Choppy OTA playback of recordings on new Media Center computer.

Hello,
I am having some problems with the playback of Over the air recordings in Windows 7 home premium 64 bit Media center.
Made the decision to put up an antenna and cut off the cable company. I took my desktop PC and put in the Hauppauge WinTV-HVR-2250 Dual TV Tuner card and set up media
Center while I built a Media center computer piece by piece.
My old computer and media center worked great from the start, great picture smooth playback, and the DVR feature of Media center made our decision to drop cable a lot less painful!
I finally get the dedicated computer finished and all the latest drivers installed. The picture is still great but playback is at times not very smooth sometimes worse than others. The motion in the recordings is odd. I don’t know if this dropping frames? This PC has a minimum of software and should have most of its resources available.

The old setup used the onboard graphics and was great. The dedicated computer should have more capability than the old. Some info on both setups is listed below.
If any one can help me solve this problem it would be greatly appreciated.

Old computer…
ASUS M4A89GTD PRO AM3 AMD 890GX HDMI SATA 6Gb/s ATX AMD Motherboard

AMD Phenom II X4 945 Deneb 3.0GHz Socket AM3 125W Quad-Core Processor

Kingston HyperX 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)

Microsoft Windows 7 Home Premium 64-bit

Hauppauge WinTV-HVR-2250 dual tuner card


New MediaCenter computer…
AMD Phenom II X4 840 Edition Deneb 3.2 GHz 4x512 KB L2 Cache Socket AM3 95W Quad-Core Processor

ASUS M5A88-M AM3+ AMD 880G HDMI SATA 6Gb/s USB 3.0 Micro ATX AMD Motherboard

ASUS EAH5450 SILENT/DI/1GD3/V2(LP) Radeon HD 5450 1GB DDR3 PCI Express 2.1 x16 HDCP Video card

Seagate Barracuda Green ST1500DL003 1.5TB 5900 RPM 64MB Cache SATA 6.0 Gb/s 3.5" Internal Hard Drive

Hauppauge WinTV-HVR-2250 dual tuner card

OCZ ModXStream Pro 500W Modular High-Performance Power Supply

Crucial Ballistix sport 4GB 240-Pin DDR3 SDRAM DDR3 1333 Desktop Memory

Microsoft Windows 7 Home Premium SP1 64-bit - OEM