We upgraded last fall and had no problems for about a week, then started getting TX32 errors and losing messages we were pulling from a file system gateway. It took a while to figure out as it was not predictable --> when I turned on the trace as requested by Sterling, the behavior changed! The finally traced it to an out-of-bounds array index and sent me a patch. Things have been OK since then. I hope you guys have the patch....
The maps translated and ran fine. We're not doing anything more with 4.0 than we were on 3.1, which makes me wonder why we switched so quickly in the first place. Now where did that consultant go.... : )
Good luck.