batch renders come darker than non batch

[cynopy]

when rendering the same frame, (same variables all across the board, lighting, gamma, peak, all that stuff) my batch renders come out darker than the non batch renders. individually rendering 10000+ frames is not an option and the batch render isnt producing acceptable results. would really appreciate any ideas on what is going on.

[goldfish]

I'll double this -- with the additional remark that they sometimes come out brighter than non-batch. Here are two attractors (with links to photobucket) rendered in the gui version (0.3.1) vs. the commandline version (0.3.5, with higher render steps). One is seriously under-, the other overexposed. While I provided "unravel" based ones, the problem has manifested itself with essentially all the fractal types.
If needed, I will provide the definition files.

http://i1104.photobucket.com/albums/h336/quinyu/unravelnoblemetalflakes01.jpg
http://i1104.photobucket.com/albums/h336/quinyu/unravelnoblemetalflakes01faulty.jpg
http://i1104.photobucket.com/albums/h336/quinyu/unravelmakeitfast01.jpg
http://i1104.photobucket.com/albums/h336/quinyu/unravelmakeitfast01faulty.jpg

I beg you, please fix this.
Peter Sisak (p-kun80 @ removedis.hotmail.com)