This morning, Microsoft released SQL Server 2008 R2 SP1 CU6, which is Build 10.50.2811.0. This Cumulative Update lists 20 fixes in the public fix list. Remember, this CU is only for SQL Server 2008 R2 Service Pack 1.
Of particular interest to me is a fix for Error 18056, State 29, which is an issue that I have encountered at both NewsGator and at Avalara. Over the past three years, I opened three Connect items about the issue, and opened three CSS cases, but unfortunately never really got the issue 100% resolved. I freely admit that this is an intermittent, complex issue that would be very difficult to debug and resolve, and I appreciate the efforts of everyone at Microsoft who helped work on this over the years. I also want to thank Aaron Bertrand (blog|twitter) for helping to focus attention on this issue.
One caveat I want to throw out is that there are many reasons you might get Error 18056, with various different State numbers. This fix is targeted at Error 18056, State 29 only, and it is not guaranteed to fix that issue in every single situation. If you have been seeing Error 18056, State 29, I would definitely get SQL Server 2008 R2 SP1 CU6 installed and see if that helps. If it does not help, then you should open a Connect item, and then open a support case with Microsoft CSS.