ammonium sulfate precipitation of proteins

[bipin dalmia]

i had 60 ml of 3 mg/ml protein solution, in 50 mM tris-hcl, 1 mM EDTA, pH
8.6. 
i wanted to concentrate it before size exclusion chromatography so i
decided to do a 85% ammonium sulfate precipitation. i added 36.6 grams of
salt (slowly) to the 60 mL at room temp. and let it stir for 30 minutes
after adding the last bit of salt. i saw the solution go all cloudy. then
centrifugation at 20,000 g for 20 minutes and NO PELLET!!! can someone
explain what happened and how i can recover my protein?

the protein that i am precipitating does precipitate at 70% ammonium
sulfate saturation from a crude extract. the 3 mg/ml solution was a
pooled fraction from an ion-exchange step that was greater than 80% pure.

bipin