DVD Ripper FIXED BITRATE Doesn't Work for MP4

[AntonioMX5]

New user trying latest release 7.0.4.0 on WinXP using ipod.mp4 profile, desiring to set a specific, FIXED Bitrate (usually either 1500 kbps or 2500 kbps for use on my iPhone for Widescreen TV playback ("TVOut")).

The PROBLEM is that no matter what FIXED Bitrate I specify, DVDFab refuses to follow what I set, defaulting to an unknown, unspecified fixed bitrate very different from what I preselected...

For example, my last attempt using the movie "Legion":
1-pass 2500 kbps specified Fixed Bitrate actually resulted in 1400 kbps
2-pass 2500 kbps specified Fixed Bitrate: same 1400 kbps as 1-pass
2-pass 1200 kbps specified Fixed Bitrate tested: same 1400 kbps

I tried installing the latest beta release (verion 7.0.5.5?) and got the same erroneous results.

Note that using the H.264 codec works flawlessly for fixed bitrate, resulting in a fixed bitrate that is exactly what I specified, whether it be 1500, 2500 or some odd number like 2250 or what not (A/V sync issues are another matter for another thread, sigh...).

So what's going on with MP4 FIXED BITRATES??? Why don't they match what I specify? What's the point of specifying a fixed bitrate if DVDFab just picks its own uknown number?

[AntonioMX5]

Additional Info

Forgot to mention this fixed bitrate problem with mp4 occurs with ALL Titles. The fixed bitrate arbitrarily chosen by DVDFab on its own varies widely, depending on the title, from as low as 1100 kbps to as high as 3650 kbps.

Sometimes it comes out close, to like 2200 when I wanted 2500 and I accept that, but that is not how it's supposed to work!