I mean whats the difference anyways ?
The frame rate for NTSC video is 29.97 fps. The frame rate of your Action file is 30.00 fps. Here is a detailed explanation and probably more than you ever care to know.
https://www.ecuad.ca/~mrose/pdf_documents/timecode.pdf
If you’ve set your project frame rate to a true 30fps, there is no need to Disable Resample, assuming that the recording was made at 30 fps. If recorded at 60 fps, then you should Disable Resample.
Since you are still having problems, have you tried simply “playing” the file in something like VLC or Media Player Classic-Home Cinema and if so, do you get the same flicker?
If the answer is “no”, you could always transcode your Action avi file using Virtualdub into an avi file with a codec that is known to work well with Vegas such as Cineform, Magic YUV, UT video, or Lagarith.
You could also upload a short clip for testing by other forum members or render the clip to YT.
wwaag