diff -ur cygwin-snapshot-20080219-1/winsup/cygwin/shared.cc cygwin-snapshot-20080219-1-noelbk/winsup/cygwin/shared.cc
--- cygwin-snapshot-20080219-1/winsup/cygwin/shared.cc	2007-12-13 04:55:41.000000000 -0800
+++ cygwin-snapshot-20080219-1-noelbk/winsup/cygwin/shared.cc	2008-02-21 16:06:33.156250000 -0800
@@ -39,8 +39,15 @@
 {
   extern bool _cygwin_testing;
 
-  __small_sprintf (ret_buf, "%s%s.%s.%d", cygheap->shared_prefix,
-		   cygwin_version.shared_id, str, num);
+  // Noel Burton-Krahn <noel@burton-krahn.com> - Feb 21, 2008 
+  // always add USER_VERSION_MAGIC to the shared memory space name so
+  // multiple versions of Cygwin all have their own memory space.
+  __small_sprintf(ret_buf, "%s%s.%s.%d.%d"
+		  ,cygheap->shared_prefix
+		  ,cygwin_version.shared_id, str, num
+		  ,USER_VERSION_MAGIC
+		  );
+
   if (_cygwin_testing)
     strcat (ret_buf, cygwin_version.dll_build_date);
   return ret_buf;