colorful bar at the bottom with filters enabled (when input have odd height)

[ami_stuff]

there is visible a colorful bar at the bottom in the output when some filters are enabled and the input have odd height

C:\>ffmpeg -i 190_129.avi -vf negate,vflip,scale=200:200 out.avi
ffmpeg version N-40290-g2330eb1 Copyright (c) 2000-2012 the FFmpeg developers
  built on May  3 2012 02:20:32 with gcc 4.5.0 20100414 (Fedora MinGW 4.5.0-1.fc
14)
  configuration: --prefix=/var/www/users/research/ffmpeg/snapshots/build --arch=
x86 --target-os=mingw32 --cross-prefix=i686-pc-mingw32- --cc='ccache i686-pc-min
gw32-gcc' --enable-w32threads --enable-memalign-hack --enable-runtime-cpudetect
--enable-cross-compile --enable-static --disable-shared --extra-libs='-lws2_32 -
lwinmm' --extra-cflags='--static -I/var/www/users/research/ffmpeg/snapshots/buil
d/include' --extra-ldflags='-static -L/var/www/users/research/ffmpeg/snapshots/b
uild/lib' --enable-bzlib --enable-zlib --enable-gpl --enable-version3 --enable-n
onfree --enable-libx264 --enable-libspeex --enable-libtheora --enable-libvorbis
--enable-libfaac --enable-libxvid --enable-libopencore-amrnb --enable-libopencor
e-amrwb --enable-libmp3lame --enable-libvpx --disable-decoder=libvpx
  libavutil      51. 49.100 / 51. 49.100
  libavcodec     54. 17.101 / 54. 17.101
  libavformat    54.  3.100 / 54.  3.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 72.103 /  2. 72.103
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 11.100 /  0. 11.100
  libpostproc    52.  0.100 / 52.  0.100
Input #0, avi, from '190_129.avi':
  Duration: 00:00:05.96, start: 0.000000, bitrate: 1626 kb/s
    Stream #0:0: Video: cinepak (cvid / 0x64697663), yuv420p, 190x129, 25 tbr, 2
5 tbn, 25 tbc
w:190 h:129 pixfmt:yuv420p tb:1/1000000 sar:0/1 sws_param:flags=2
[scale @ 0x1dc2ca0] w:190 h:129 fmt:yuv420p sar:0/1 -> w:200 h:200 fmt:yuv420p s
ar:0/1 flags:0x4
Output #0, avi, to 'out.avi':
  Metadata:
    ISFT            : Lavf54.3.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 200x200, q=2-31, 200
 kb/s, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (cinepak -> mpeg4)
Press [q] to stop, [?] for help
frame=  149 fps=0.0 q=14.8 Lsize=     261kB time=00:00:05.96 bitrate= 358.8kbits
/s
video:252kB audio:0kB global headers:0kB muxing overhead 3.618119%