What to do with “The version of SOS does not match the version of CLR you are debugging” in WinDbg?

Question

I'm having a problem with some of my apps. It's a wcf-based app running under IIS6 in Windows 2003 Server (x86):
In Event Log I get such an error from "W3SVC-WP" source (EventID=2262):

ISAPI 'C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll' reported itself as unhealthy for the following reason: 'Deadlock detected'.

I'm trying figuring out what's going on. I've set up creating dump for Orphan Worker Process as described in this KB. When an deadlock occured a minidump is created.
Then I take this minidump to try to understand what's happened. Here's I'm stuck.

I run WinDbg x86, open my dump and then:

0:037> .loadby sos clr
0:037> .sympath SRV*c:\temp\symbols*http://msdl.microsoft.com/download/symbols
Symbol search path is: SRV*c:\temp\symbols*http://msdl.microsoft.com/download/symbols
Expanded Symbol search path is: srv*c:\temp\symbols*http://msdl.microsoft.com/download/symbols
0:037> !clrstack
The version of SOS does not match the version of CLR you are debugging.  Please load the matching version of SOS for the version of CLR you are debugging.
CLR Version: 4.0.30319.1
SOS Version: 4.0.30319.235
CLRDLL: C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\mscordacwks.dll:4.0.30319.235 f:8 doesn't match desired version 4.0.30319.01 f:8
CLRDLL: Loaded DLL c:\temp\symbols\mscordacwks_x86_x86_4.0.30319.01.dll\4BA1D9EF66f000\mscordacwks_x86_x86_4.0.30319.01.dll
OS Thread Id: 0x690 (37)
Unable to walk the managed stack. The current thread is likely not a managed thread.
You can run !threads to get a list of managed threads in the process

What to do with this error - "The version of SOS does not match the version of CLR you are debugging" ?

The same error ("The version of SOS does not match the version of CLR you are debugging") I'm getting when I open the minidump in VS2010.

I've read this post - http://tech-thinker.com/Forums/tabid/62/forumid/12/postid/471/scope/posts/Default.aspx, and tried installing KB2518870. It doesn't help.