I updated a good portion of my Web Edition training apps tonight to 2011 R2 and discovered something new (after banging my head up against the wall for several hours). It seems that in R2, using the Application Identifier property is not only a good idea, but a necessity if you have have multiple web apps running.
What happens if you don’t have the Application Identifier property set? Your first app will start just fine. But subsequent apps will fail. I finally figured that out after looking at my server log and seeing entries like this:
malformed header from script. Bad header=Another instance of com.yourco: myapp, referer: http://www.bkeeney.com/realbasic-training-section
Once I recompiled the apps with unique app identifiers they loaded no problem. So the lesson is to make sure you have unique identifiers for all of your Web Edition apps.
Hopefully this saves you some time (and a bit of skin). And maybe it will solve a mystery for you.