I haven't been able to figure it out from the schematics, my brain doesn't do EE type stuff well at all.

However, hotwiring a line driver IC into your CoPro CS jumper to n.c. pin 2 on the PDS might be something that could help. If it's n.c. and you're going straight from CoPro CS on the MoBo to the PDS pin, I'd guess that could be problematic, even if it appears to work correctly without the extra oomph.