BizTalk configuration broken following WCF hotfix installation

I usually post over on StackOverflow, but thought this was probably better suited to ServerFault. Please migrate if I'm wrong!

I am developing a WCF service and a BizTalk application on my workstation at the moment. As part of the WCF service, I had to install hotfix 971493 from Microsoft which updates some core WCF assemblies.

Following installation of that hotfix, I am now experiencing severe issues in my existing BizTalk application. When I attempt to configure the properties of an existing WCF-Custom receive location, I get this error:

Error loading properties (System.IO.FileLoadException) The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

If I click OK (the same error repeats four times) I eventually see the WCF-Custom properties dialog. However if I click on the various tabs, I continue to receive errors:

The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) (Microsoft.BizTalk.Adapter.Wcf.Admin)

The WCF-Custom receive location was working yesterday, and I installed the hotfix this morning. I'm guessing these two are related, and that BizTalk somehow has a reference to the old WCF assemblies.

Does anyone know how I can fix this?

Another hour of fiddling and I sorted it out.

I installed Cumulative Update Package 6 for BizTalk Server 2009. It failed and rolled back the first time, but on a second attempt it was successful.

I went back into BizTalk Administration Console and the WCF-SQL configuration options were back to normal with no error messages.

I wonder if a BizTalk Server 2009 repair installation would have had a similar effect.