Discussion about the Korg PolySix synthesizer

hi guys, so my apologies for the period between posts, but i had a very busy 1st half of 2010. anyway, i had posted a while back with a P6 problem:

LFO will not be modulated at VCF or VCA, only VCO, in the MG section.

in relation to the KLM367 board:
someone had suggested replacing IC13-a 4558 opamp, which i swapped, as well as IC15 and the .33uf cap right next to it. no change, same problem.

any suggestions further on where the culprit might be? im assuming its got to be around the lm3700's on the board. thanks for the help.