Adobe Premiere Pro: rendered video jitter (frames jump around)

Question

Perhaps not exactly the best forum for this as it may be slightly out-of-topic. On another hand the community is great and helpful.

Using Premiere Pro CS5, my machine is well rounded and shouldn't be the issue. More likely I need tips and directions about how to use the software.

I'm editing a screen capture and synchronizing it with video taken from a webcam. The webcam video will be a Picture-in-Picture in the screen capture. I have jittering issues or speed issues, depending on sequence settings. I don't know if "jitter" is the word. It just jumps to a frame in the future then back and so forth. For the "speed" it just plays twice as fast. I tried two different Sequence settings, and several export media settings for each. The first sequence was the default sequence offered by Adobe Premiere Pro, the second sequence I tried to it set to match the end product (Desktop) and the framerate of the fastest input (30fps). I am replaying in VLC.

Screen capture: MS MPEG-4 Video v2 (MP42) @ 30 fps
Webcam: MS MPEG-4 Video (FMP4) @ 10 fps

[1]
Sequence: AVC-Intra 100 720p 50Hz @ 25 fps, square pixels, progressive scan, 25 fps Timecode
Video preview: I-Frame Only MPEG

Export Media
[1.1] DV Video (dvsd) @ 25 fps
[1.2] MPEG-1/2 Video (mpgv) @ 50 fps
[1.3] AVI NTSC DV 24p
[1.4] Match Sequence Settings
[1.5] MPEG-2 HDTV 720p @ 30 fps

Preview plays fine. Rendered videos is jittering, for all export media settings. For [1.5] VLC codec media information tells me that the Framerate is 60fps (and not the 30fps that I asked); however GSpot says 30 fps.

[2]
Sequence: Desktop @ 30 fps, square pixels, progressive scan, 30 fps Timecode
Video preview: I-Frame Only MPEG

Export Media
[2.1] Match Sequence Settings
[2.2] MPEG-2 HDTV 720p @ 30 fps
[2.3] Microsoft AVI NTSC DV @ 29.97 fps

Preview plays fine. Here the screen capture is playing way too fast, while the webcam is fine. In 2.1 and 2.2 the screen capture finishes before the end of the video. In 2.3 the screen capture still play faster but loops to fill up the length of the sequence. VLC codec media information tells me that the Framerate is 60fps (and not the 30 fps that I asked); however GSpot says 30 fps.

What sequence setting should I use for producing my video? The goal is to play it on a computer. What render setting should I use? I want to avoid jitter or accelerated play issues.

Thank you.