AKAI may be contacted through the MPC4000 group on Yahoo! but it isn't going to do any good. They are a small company with limited resources. It wouldn't surprise me to hear their staff has no more than a dozen employees. They don't have a huge budget for R&D. For all you know there never will be another large MPC like the 4000. AKAI has had 2 years to fix the 4000. They can't even do that, let alone develop a better model than that one.
Group members from Yahoo! e-mail AKAI now and then. E-mail addresses for AKAI were posted there recently. Nothing gets done. David Whittle has been a very patient interface between AKAI users and his company. After the OS 1.5 fiasco even he must be losing faith.