As you may have heard, there is an issue in the BizTalk 2006 R2 and 2009 EDI Engines that results in a failed EDI transaction if the EDI message contains a date node that has a leap year value - for example 2/29/2012. This issue and hotfix is documented at http://support.microsoft.com/kb/2435900. With 2/29/2012 just days away, this is a big deal and you will want to address this issue in your environment ASAP.
You can also get some great information about this issue at http://blogs.msdn.com/b/biztalkcrt/archive/2012/02/22/edi-leap-year-hotfix-biztalk-2009-and-biztalk-2006-r2.aspx.
I've also compiled a list of questions that have been asked about this issue over the last week and created a detailed FAQ document about this. Check it out below.
Also, to download the pipeline sample mentioned in the FAQ, click here.
(FAQ last updated on 02/29/2012 at 12:22PM Central Time)