Workaround

src/E621.cpp

@@ -593,8 +593,8 @@ void E621::check_state()
 		command(cmd.str(), rep);
 		/* Sometimes ONT? returns three characters which
 		 * the first one is BELL that should be removed */
-//		if (rep[0] == 0x7)
-//			rep.erase(rep.begin());
+		if (rep[0] == 0x7)
+			rep.erase(rep.begin());
 		/* ONT? reply is always two characters */
 		assert(rep.size() == 2);