Red Ale Problems???

I tried this recipe a month ago or so and followed all my usual sanatizing and bottling procedures but the beer ended up being over carbonated. In 8 years of brewing this has never happened. The beer would fiz like normal and then about 3 seconds after opening carbonation would come up from the sediment at the bottom of the bottle and literally fiz away half the beer.

Recipe
7lbs Light Malt Extract
1lb Light DME

1lb Numich
2 oz Black Roated
.5 oz Crystal 120L

Hops - .5 oz Munich 60 min
2 oz williamette 1 min

Whirfloc at 20 min

Corn Sugar for bottling.

The brew was in the primary fermentor for 10 days and then in the bottle for 10 days prior to popping the first bottles.

Any thought on why the bottles were over carbonated?

Wow that's fast carbing...

First off, I'd recommend using a secondary for a at least a week or so after primary ferment from now on to reduce your sediment a little more and help age the beer.

Second, how much priming sugar did you use, and how big was your batch?

Third, did you mix your priming sugar in a bucket with the wort thoroughly, or just put in bottle?

Since you've been doing it the same way for so long with good results, maybe it just wasn't done fermenting yet.

+1 on a secondary or at least more time in the primary,

I'm betting it wasn't fermented out completely before you bottled, if the yeast were still active and you re-fed them, that could explain the speed and not being done with the original sugar would explain the over carbonation.

Bottle bombs are possible in this scenario you might want to store them out of the way

I agree with budbo on it not being fermented completely by the time you bottled. I made the same mistake with a hefeweizen a while back.

Also, what temperature were the bottles stored at? And how much corn sugar did you add during bottling?

No off flavors or anything? I had a gusher infection on a batch once and the same thing happened, but there were definitely some issues with that beer.