Changing the bit rate doesn't seem to work

[Drewster]

As a test to find preferred size versus quality I am transcoding MPEG-2 clip to AVI, and keeping all settings the same except video bit rate. Problem is the AVI output files all have about the same bit rate (1170s) regardless of what bit rate I set the job to; I've tried 1313, 1530, 1775, 1970, 2188, and 2911 (testing different bits/pixel).

I run one job at a time and for each change just the video bit rate. According to Media Info all have about the same bit rate. File sizes, too, are about the same and quality is hard to distinguish, so I don't think it's a header issue.

These are my settings. I use the generic.avi.divx.mp3 profile:
1: encoding= 1-pass encoding
2: bitrate= variable (I want to see bits/pixel of 0.15, .20, .25)
3: split= no
4: framerate= same as source
5: set a custom resolution of 720x405 (aspect ratio of 1.78 or 16:9) ... interestingly enough, the resultant files when played in VLC look squished and I have to set aspect ratio one level higher, in this case 2.21
6: audio bitrate= 128 kbps
7: channel= prologic-ii
8: subpicture= no subpicture

I searched the forums and googled but didn't find this asked and answered; forgive me if I missed it. I'm using DVDFab v6.2.1.8. I have not tried using another container (e.g. MP4) or rebooting.

SOURCE FILE
General
Complete name : filename.mpg
Format : MPEG-PS
File size : 11.0 MiB
Duration : 26s 400ms
Overall bit rate : 3 509 Kbps
Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, Matrix : Default
Duration : 26s 342ms
Bit rate mode : Variable
Bit rate : 2 922 Kbps
Nominal bit rate : 9 800 Kbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Standard : NTSC
Colorimetry : 4:2:0
Bits/(Pixel*Frame) : 0.282
Stream size : 9.17 MiB (83%)
Audio
ID : 129 (0x81)
Format : AC-3
Format/Info : Audio Coding 3
Duration : 26s 400ms
Bit rate mode : Constant
Bit rate : 448 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Surround: L R, LFE
Sampling rate : 48.0 KHz
Stream size : 1.41 MiB (13%)
Text
ID : 224 (0xE0)-DVD-1
Format : EIA-608
Muxing mode : MPEG Video / DVD-Video
Muxing mode, more info : Muxed in Video #1
Stream size : 0.00 Byte (0%)

Thank you for any help you can provide!

[Complication]

The clip may be too small to effectively manipulate the bitrate. Try something that is at least 5 minutes long if you would like to see a difference. DVDFab is designed to arrive at the requested average bitrate over movie length content so it may not have the precision at one hundredth the normal movie size.