PREMEIRE PRO timeline:avi video looks bad but audio is ok

[GalacticoX4]

I'm new to editing so sorry if this is elementary.

Problem:
i have several random clips. When i combine them in a timeline sequence some files in the sequence play fine but others have perfect audio but the video is garbled static, snowy or just a black screen.

Info that may help:
1) in premeire pro there are two preview windows under "monitor". all the videos play perfect if played in the left (middle) window but poorly in the right (sequence 01) window.
All files play perfect in Windows Media player 9 and in Real player.

my system:
Pentium III 800E, geoforce 2 mx card, 512 mb ram, win xp pro all updates. tons of codecs installed. (i know it sucks i plan to upgrade soon)

Here is codec info on the clips that play wrong, retrieved using G-Spot 2.21.
1. all the videos are .avi video is "4CC: DX50/divx NameX50/divx, audio is MPEG-1 Layer 3. 480x288 sound is fine the video is black and has occasional snow and lines.

all other file types seem to work fine. Any help you could provide would be greatly appreciated.

Thank you.

[Baldrick]

please do not cross post.