On July 12, we let you know that some users were experiencing "UnknownID" errors when using xIdentifier services (xISBN, xISSN, and xOCLCNum) and that our investigation had revealed a problem with the data in the source database going back to May 2012. I'm happy to tell you that work on the database is already underway and we anticipate it will be complete - resolving the problem - by the end of this week. We'll update you if anything changes.
Again, we apologize for any inconvenience.
I am still interested in hearing more from you about how you currently use these services - or would like to be using them - and what enhancements you'd like to see. Please drop me a note at firstname.lastname@example.org and let me know what you think.