Encoder Settings for DVD Output

[Tojo4158]

I've been trying to transcode some videos (MP4 with H.264/AVC codec) to DVD and keep ending up with resultant videos that have momentary choppiness throughout the video during DVD playback and in some cases have more serious drop outs for a half second or so.

My process has been to use Avidemux to cut and transcode to a compliant mpg file and then use DVD Styler in a copy mode to author the DVD without further transcoding.  However, I'm not sure I'm getting compliant mpg files from Avidemux.

Given the issue at hand, I've focused mostly on bit rate assuming it might be too high for DVD playback.  Sure enough, the MPEG Validator tool indicates that I have a non-compliant mpg file and that one of the issues is the peak bit rate of 11.8 Mpbs vs a max allowable of 9.8 Mbps for DVD.  The tool gives me the timecode of the peak which corresponds to one of the "serious" drops in the video/audio playback.  But there are other smaller "jitters" in the playback throughout. 

What I can't understand is why I have a peak of 11.8 Mbps.  I'm using the following settings to attempt to get the highest quality compliant DVD video I can.

Video output Mpeg2 (ff)
    Widescreen aspect ratio
    Two Pass Avg Bitrate
    6000 kbps
    224 VBV Buffer
    2 B Frames
    15 GOP
    8000 kbps Max Bitrate
    Progressive
    Rate distortion macro block detection
    1 Min Quant
    6 Max Quant
    2 Max Quant Diff
    No Trellis quant
    2000 kb filesize tolerance
    0.7 Quant compression
    0.7 Quant blur
Filters
    swResize 720x480
    Resample 29.97 NTSC

Audio settings AC3 (lav):
    128 kbps

Output Format Mpeg-PS Muxer (ff):
    Muxing Format DVD


Does the encoding process completely ignore the Max Bitrate field, or what could cause the output to go above the value listed in this setting? 

Any other advice that can be given to help create a compliant file with the highest reasonable quality (reasonable, meaning the output is at least close to fitting on a 4.7GB DVD-R).

Thanks