I am running multi-db with a shopping cart backend

I am running multi-db with a shopping cart backend ShopPlugin. I came across a thread on your website regarding integration of the two that was 4 years old, but my symptoms are virtually identical. I was wondering what we can do to fix the issues we are having? The link to the thread is: https://premium.wpmudev.org/forums/topic/shopp-plugin-and-multi-db. If you could get back to me ASAP I would appreciate it as we are currently having issues with our system because of this.