diff --git a/profile/src/nsProfileAccess.cpp b/profile/src/nsProfileAccess.cpp
index 95faa5a09dad..60aa9981345f 100644
--- a/profile/src/nsProfileAccess.cpp
+++ b/profile/src/nsProfileAccess.cpp
@@ -50,9 +50,11 @@
 
 #if defined (XP_UNIX)
 #define USER_ENVIRONMENT_VARIABLE "USER"
+#define LOGNAME_ENVIRONMENT_VARIABLE "LOGNAME"
 #define HOME_ENVIRONMENT_VARIABLE "HOME"
 #define PROFILE_NAME_ENVIRONMENT_VARIABLE "PROFILE_NAME"
 #define PROFILE_HOME_ENVIRONMENT_VARIABLE "PROFILE_HOME"
+#define DEFAULT_UNIX_PROFILE_NAME "default"
 #elif defined (XP_BEOS)
 #endif
 
@@ -1013,8 +1015,6 @@ nsProfileAccess::ProfileExists(const PRUnichar *profileName)
 nsresult
 nsProfileAccess::Get4xProfileInfo(const char *registryName)
 {
-    NS_ASSERTION(registryName, "Invalid registryName");
-
     nsresult rv = NS_OK;
     mNumOldProfiles = 0;
 
@@ -1023,6 +1023,8 @@ nsProfileAccess::Get4xProfileInfo(const char *registryName)
     if (NS_FAILED(rv)) return rv;
 
 #if defined(XP_PC) || defined(XP_MAC)
+    NS_ASSERTION(registryName, "Invalid registryName");
+
     nsCOMPtr<nsIRegistry> oldReg(do_CreateInstance(NS_REGISTRY_CONTRACTID, &rv));
     if (NS_FAILED(rv)) return rv;
     rv = oldReg->Open(registryName);
@@ -1118,16 +1120,20 @@ nsProfileAccess::Get4xProfileInfo(const char *registryName)
 #elif defined (XP_BEOS)
 #else
 /* XP_UNIX */
-        char *unixProfileName = PR_GetEnv(PROFILE_NAME_ENVIRONMENT_VARIABLE);
-        char *unixProfileDirectory = PR_GetEnv(PROFILE_HOME_ENVIRONMENT_VARIABLE);
+        nsCAutoString unixProfileName( PR_GetEnv(PROFILE_NAME_ENVIRONMENT_VARIABLE) );
+        nsCAutoString unixProfileDirectory( PR_GetEnv(PROFILE_HOME_ENVIRONMENT_VARIABLE) );
 
-        if (!unixProfileName || 
-            !unixProfileDirectory || 
-            (PL_strlen(unixProfileName) == 0) || 
-            (PL_strlen(unixProfileDirectory) == 0)) 
+        if (unixProfileName.IsEmpty()  || 
+            unixProfileDirectory.IsEmpty())
         {
-            unixProfileName = PR_GetEnv(USER_ENVIRONMENT_VARIABLE);
             unixProfileDirectory = PR_GetEnv(HOME_ENVIRONMENT_VARIABLE);
+            unixProfileName = PR_GetEnv(LOGNAME_ENVIRONMENT_VARIABLE);
+            if ( unixProfileName.IsEmpty() ) {
+              unixProfileName = PR_GetEnv(USER_ENVIRONMENT_VARIABLE);
+            }
+            if ( unixProfileName.IsEmpty() ) {
+              unixProfileName = DEFAULT_UNIX_PROFILE_NAME;
+            }
         }
 
         PRBool exists = PR_FALSE;;
@@ -1137,7 +1143,7 @@ nsProfileAccess::Get4xProfileInfo(const char *registryName)
             return NS_OK;
         }
 
-        if (unixProfileName && unixProfileDirectory) {
+        if ( ! unixProfileName.IsEmpty() && ! unixProfileDirectory.IsEmpty() ) {
             nsCAutoString profileLocation(unixProfileDirectory);
             profileLocation += "/.netscape";
             nsCOMPtr<nsIFileSpec> users4xDotNetscapeDirectory;