diff --git a/indra/llcommon/llapr.cpp b/indra/llcommon/llapr.cpp
index c0ca69f42d..8ab7f5bcea 100644
--- a/indra/llcommon/llapr.cpp
+++ b/indra/llcommon/llapr.cpp
@@ -158,7 +158,17 @@ LLVolatileAPRPool::LLVolatileAPRPool(BOOL is_local, apr_pool_t *parent, apr_size
 				  mMutexp(NULL)
 {
 	//create mutex
-	if(!is_local) //not a local apr_pool, that is: shared by multiple threads.
+
+	// <FS:ND> Crashfix/FIRE-4090/FIRE-4820: is_local is default to TRUE. And of today (2012-07-15) all instances of LLVolatileAPRPool seem
+	// to be created just using this default argument.
+	// Using apr_os_thread_current and apr_os_thread_equal it appears that there are pools that get access from different threads nonetheless.
+	// This would explain why mNumActiveRef sometimes gets garbled.
+	// Resolution: Always use a mutex and give it a broader test is this helps.
+
+	//	if(!is_local) //not a local apr_pool, that is: shared by multiple threads.
+
+	// </FS:ND>
+
 	{
 		apr_pool_create(&mMutexPool, NULL); // Create a pool for mutex
 		apr_thread_mutex_create(&mMutexp, APR_THREAD_MUTEX_UNNESTED, mMutexPool);