darkness in video after compression

[MLane2250 at aol.com]

HI folks:

The video that I view after it has been compressed and distributed by CD-Rom 
is significantly darker than the original, uncompressed footage.  I assume 
this is strictly a result of compression.  I typically use Sorenson.  It 
seems to happen regardless of fps but I do generally limit transfer rate to 
100 Kbs to compensate for CD-Rom.

Any suggestions to lighten up the results and not look so gothic?

Thanks.