When computing and saving twice a log file for the same process, memprof crashes. The issue is in main.c, both for functions save_leak_cb and save_profile_cb where some memory is freed twice. The following patch on file main.c solves the issue:
@@ -1098,11 +1098,12 @@
                filename = get_filename ("Save Leak Report",
                                         suggestion ? suggestion : "memprof.leak");
                if (filename) {
-                       g_free (suggestion);
+                       if(suggestion){ 
+                               g_free (suggestion); 
+                       }
                        suggestion = filename;
 
                        leaks_print (pwin->process, pwin->leaks, filename);
-                       g_free (filename);
                }
        }
 }
@@ -1119,11 +1120,13 @@
                filename = get_filename ("Save Profile",
                                         suggestion ? suggestion : "memprof.out");
                if (filename) {
-                       g_free (suggestion);
+                       if(suggestion){ 
+                               g_free (suggestion); 
+                       }
+
                        suggestion = filename;
 
                        profile_write (pwin->profile, filename);
-                       g_free (filename);
                }
        }
 }