"Foam resistance
Poor lubrication can result from foam. Oil pressure loss and hydraulic lifter noise can be caused by foam. Over-filling the crankcase can contribute to crankshaft “windage” which contributes to oil foaming. Foam can be reduced by foam inhibiting additives which affect the oil’s surface tension."

from:
http://www.nutidltd.co.uk/sub_page.cfm?id=132

Heat can also cause oxidation... I remember reading that the use of forward/reverse trying to 'rock' a car out of a hole....can quickly raise the temperature of the transmission fluid .... and that at a certain point every 10 degree rise halfs the effective life of the fluid...
In other words.... you might sit there for ten minutes and completely ruin your trans fluid... you would need to replace it as soon as possible...

Windage trays...
http://www.google.com/search?hl=en&lr=&q=windage+trays+&btnG=Search
Hot Rods in the 1960's used them... and now many regular engines come with them....