Use the appropriate timing.

Restores Page Up/Page Down/;/' properly.

src/ScreenEdit.cpp

@@ -1348,7 +1348,7 @@ void ScreenEdit::InputEdit( const InputEventPlus &input, EditButton EditB )
 			m_iShiftAnchor = -1;
 		return;
 	}
-	TimingData &sTiming = GAMESTATE->m_pCurSong->m_SongTiming;
+	TimingData &sTiming = GetAppropriateTiming();
 	float playerBeat = GetAppropriatePosition().m_fSongBeat;
 	int beatsPerMeasure = sTiming.GetTimeSignatureSegmentAtBeat( playerBeat ).GetNum();