That's pretty high at 136 F (58 C) at idle. My Athlon 1.9 overclocked to 2.0 (actually a bit faster) runs at 39-40 C (102-104 F) at idle, and 50 C (122 F) if I'm running something stresing, like Return to Castle Wolfenstein, or using WinRAR to compress files at highest compression. For your temperature at 1.3, I'd either get a better heat sink/fan combo, or first, open the case and see if the temp goes down. If it does, get a higher flow case fan, or add another one (or both). For comparison, if you know your motherboard temp, mine runs at 31 C idle. If it was me, I wouldn't run your system any higher without better cooling. Even your non-overclocked idle temp is higher than my system overclocked and stressed.
Hope I got the temp convesions right.
NoSpam