Actually StockSubmitter also uses Exiftool to write metadata to images.
So it there is any problem reading metadata after StockSubmitter wrote it to images, it should be some problem with Exiftool.
Also Adobe Bridge may be confused by different types of metadata in single image. StockSubmitter writes metadata in three formats - EXIF, IPTC, XMP - to make sure it is read correctly in any software.
Earlier there was no problems with reading metadata written by StockSubmitter in any program including Adobe Bridge. It is strange you have such problems now. When did you start to encounter this issue? Did you upgrade Adobe Bridge or something like that?