It's just fine. Your computer is stable. Don't worry about it. Your case w/ the regular antec fan hooked up to the fan connector on the sl350 PS will ventilate that case perfectly.
Try OCing it to 200x11 and see if it's stable, and if your temps change, on stock voltage. I would imagine it probably is.
That temp is a high for an idling barton @ stock speed though. I'd get a nice new Thermalright heatsink w/ a quiet fan. If you have the money to burn, I mean.