iTunes Store Support got back to me today and this is what the kind folks suggested:
+I see that your in app purchase is not working as expected. I understand how frustrating this must be. I can certainly appreciate how eager you must be to resolve this issue. The developer of this application, Apple Inc, is the best resource for assistance with this issue. To contact them, please visit:+
+
http://www.apple.com/support/mobileme/+
+The article below may also be helpful; I found it for you on the Apple website:+
+Troubleshooting applications purchased from the App Store+
+
http://support.apple.com/kb/TS1702+
I appreciate their help, but do they appreciate the irony of directing me to Apple Inc.?
Anyway, I've already tried the troubleshooting suggestions but to no avail.
I'll wait for the bug to be fixed with an update.
Message was edited by: pape