--- a/toolkit/components/startup/nsAppStartup.cpp
+++ b/toolkit/components/startup/nsAppStartup.cpp
@@ -867,16 +867,25 @@ nsAppStartup::TrackStartupCrashBegin(boo
   PRInt32 maxResumedCrashes = -1;
   rv = Preferences::GetInt(kPrefMaxResumedCrashes, &maxResumedCrashes);
   NS_ENSURE_SUCCESS(rv, NS_OK);
 
   PRInt32 recentCrashes = 0;
   Preferences::GetInt(kPrefRecentCrashes, &recentCrashes);
   mIsSafeModeNecessary = (recentCrashes > maxResumedCrashes && maxResumedCrashes != -1);
 
+  // Bug 731613 - Don't check if the last startup was a crash if XRE_PROFILE_PATH is set.  After
+  // profile manager, the profile lock's mod. time has been changed so can't be used on this startup.
+  // After a restart, it's safe to assume the last startup was successful.
+  char *xreProfilePath = PR_GetEnv("XRE_PROFILE_PATH");
+  if (xreProfilePath) {
+    GetAutomaticSafeModeNecessary(aIsSafeModeNecessary);
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
   // time of last successful startup
   PRInt32 lastSuccessfulStartup;
   rv = Preferences::GetInt(kPrefLastSuccess, &lastSuccessfulStartup);
   NS_ENSURE_SUCCESS(rv, rv);
 
   PRInt32 lockSeconds = (PRInt32)(replacedLockTime / PR_MSEC_PER_SEC);
 
   // started close enough to good startup so call it good