http://social.technet.microsoft.com/Forums/en-US/smallbusinessserver/thread/76cfdd73-dace-4984-8896-fdaed0dcf818/
Another user, c_h_u_c_k_o, has replied to a thread you have subscribed to in the Small Business Server Forum.
Thread Title Do not install 2506143 (optional WMF 3.0 patch) on your SBS 2011
Started by: Susan Bradley
Reply:
Unfortunately, uninstalling it apparently brings forth another problem - it deletes a registry key that causes problems and errors with your event logs.
Here is the key that is deleted:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WINEVT\Channels\ForwardedEvents
I had to export the key from another system and install it into the registry of the affected SBS2011 box to restore the ability to view the event logs without error.
Who knows what else it breaks.
This update should be pulled. NOW!

I can repro his reporting of the issue.
And as of around 5 p.m this evening:
http://marc.info/?l=patchmanagement&m=135588298213669&w=2
Thanks to each of you who reported this issue and helped identify the affec=
ted cases.
As a result of these regressions and feedback from customers and experts li=
ke you, we have expired the WMF 3.0 Update for all platforms (Windows 7, Se=
rver 2008, and Server 2008 R2) as of 5:07 pm PDT.
2506143 Windows Management Framework 3.0 for Windows 7 (KB2506143)
Windows Management Framework 3.0 for Windows 7 for x64-based System=
s (KB2506143)
Windows Management Framework 3.0 for Windows Server 2008 R2 for x64=
-based Systems (KB2506143)
2506146 Windows Management Framework 3.0 for Windows Server 2008 (KB2506146=
)
Windows Management Framework 3.0 for Windows Server 2008 for x64-ba=
sed Systems (KB2506146)
We're engaged in an internal post-mortem to identify and resolve the issues=
that led to these updates being released that resulted in the regressions.
We work hard to ensure updates always release with an exceptionally high qu=
ality bar. That bar was not met for these updates and we're working to ens=
ure we can prevent this from happening again. Thank you for your feedback =
through this and other channels - and please keep providing helpful feedbac=
k so we can continue to improve.
doug neal
Microsoft Update (MU)