[FFmpeg-user] ac3 invalid bit rate error

[tundra5280]

Have been converting dts audio to ac3 successfully with ffmpeg for almost a year.  Built a new ffmpeg executable today (ffmpeg version N-32060-g124deea) on Mac Pro running 10.7.1 and now get the following error when attempting to convert:

[ac3 @ 0x7fbe9b02f400] invalid bit rate

Error while opening encoder for output stream #0.1 - maybe incorrect parameters such as bit_rate, rate, width or height

I am also seeing:
[mpegts @ 0x7fbe9b008800] Continuity Check Failed

The conversion process does not seem to be hanging up on the continuity check but is hanging up on the ac3 error but maybe they are related.

Configure:
./configure --prefix=${TARGET} --cc=clang --enable-nonfree --enable-gpl --enable-version3 --enable-libx264 --enable-pthreads --enable-libfaac --enable-libspeex --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-libgsm --enable-libopenjpeg --enable-libxvid --enable-libschroedinger --enable-libdirac --enable-libxavs --enable-librtmp --enable-libfreetype --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-swscale --enable-avfilter --enable-filters --enable-postproc --target-os=darwin --arch=x86_64 --enable-runtime-cpudetect

My conversion command line has not changed.  The audio portion of command line:
-acodec ac3 -ab 448k -ar 48000

448k is a valid bit rate!!!

Get the same error wether the audio source is dts or ac3.

Any work arounds for this error?  Thanks in advance for help.