Do me a favor can you try completely uninstalling and reinstalling VideoReDo and see if it makes any difference? (also delete any files left over in the install directory before the reinstall) It seems that other users are having similar problems and reinstalling seems to fix them, so I'm wondering if that might the case here as well.
If you don't want to lose your settings then you can try the hack DanR describes here...
I exported, then deleted the entire HKEY_CURRENT_USER\Software\DRD Systems branch and the problem was solved.
A bit more digging and it turns out that, at least on my PC, I can cause the picture to become jerky again by changing the video brightness (View > Change Display Properties). Once I do this, IPP display becomes jerky. Any non-zero value in HKEY_CURRENT_USER\Software\DRD Systems\VideoReDo-TVSuite4\PlaybackDeviceOptions\Brightness causes it. An interesting thing I noticed is that when using VR to adjust the brightness the inital movement of the slider causes the clip shown in VR to step off the currently shown frame.
The behaviour remains the same even on a clean install of 635e (reg keys removed, directories removed etc).
A bit more digging and it turns out that, at least on my PC, I can cause the picture to become jerky again by changing the video brightness (View > Change Display Properties). Once I do this, IPP display becomes jerky. Any non-zero value in HKEY_CURRENT_USER\Software\DRD Systems\VideoReDo-TVSuite4\PlaybackDeviceOptions\Brightness causes it.
The problem happens with any MPEG-2 source I've tried, but here's the details of a program that I have confirmed it happens with.
File: Name: H:\Recordings\The Avengers Escape in Time WIN Mackay.ts
Size: 4.232 GB
Mux type: TS Stream
TS mux rate: 3.542 Mbps
Video: Encoding: MPEG2
Frame rate: 25.00 fps
Encoding size: 720 x 576
Aspect ratio: 16:9
Header bit rate: 15.000 Mbps
VBV buffer: 224 KBytes
Progressive: Prog or Int
Bit rate: 4.903 Mbps
Audio Stream: 1 (Primary) Codec: MPEG
MPEGLayer: Layer 2
PES Stream Id: xC0
Bit rate: 384 Kbps
Sampling rate: 48000
Sample size: 16 bits
Subtitle: 1-1 Type: DVB Teletext
Subtitle: 1-2 Type: DVB Teletext
Deinterlace On: unticked
Use Video Card YUV acceleration: ticked
Displayed Aspect Ratio: Auto
Video Driver: VMR9
Use Device Wave: unselected
Use Direct Sound drivers: selected
Device: Primary Sound Driver
Edit Without Audio: unselected
Swap LCPM Audio Bytes: unticked
OS: Win7 64 bit, aero on
CPU: Core i7-2600, 3.4GHz
Do me a favor and change the driver on Tools>Options>Devices from VMR9 to DirectX. When you open a video Aero will disappear but I'm curious to know if this makes a difference with the stuttering. Aero will re-appear when you close VideoReDo.
I changed VR to direct-x display but it only showed a black pane from then on (also tried disabling yuv acceleration but didn't help with the black pane) and aero remained in effect with VR open. Manually configuring Windows with a non-aero theme allowed VR to display the clip in direct-x mode, but the stutter / jerky problem was still present.