I have a copy of the Service Bulletin that I received from Steve some time ago. Post your fax # and I can send it to you.
As closure to this particular issue. It turns out the the difference between the computer Mercedes recommends upgrading to and the original is the software on the chip... and at that only 18 bytes of it.
I've run into a few additional people who have had this problem. We went ahead and simply replaced the chip with the newer version (got a copy from someone who had the new computer) and it has so far solved the issue and eliminated the check engine light #19 code.