mash yield disaster

The last time I brewed this style of beer - American Wheat/Rye Ale - I had a mash efficiency of 71.7% and overall of 60.6%. Tonight I did a slightly tweaked version of the same recipe and mashed between 150 and 152F - never outside of that for one hour ( I have a temp controlled re-circulation system). Instead of 5 gallons I got 4.25 and missed my OG by 0.002. Mash efficiency 47.5% with total efficiency 44.9%! WTF! Everything went like clockwork so I am completely baffled. What went wrong? Am I not crushing my grains enough? I usually get 67-73% efficiency in the mash - I have never had anything like this before.

Suggestions/help anyone?

I'd start by reading this thread:

http://www.beersmith.com/forum/index.php/topic,10779.0.html

Thanks Tom,

I have gone over every thing and come to the following conclusions:
1. Don't brew beer when you are sick and tired - you will make dumb mistakes.
2. I used the wrong Equipment profile so my volumes were a bit off. Had I not been sick and tired I would have realized this.
3. I skipped the protein rest
4. I do think the grains were not crushed enough
5. I did not do a good job sparging - was rushing it as I was tired and sick.

The really annoying part was this was supposed to be for a homebrew competition. I needed to get it brewed in order for it to be correctly aged for the competition. Had it been any ordinary brew I would not have attempted to brew under the circumstances. I think it will be an OK beer but not what I intended to brew, so very disappointed. I have certainly humbled myself and hopefully will learn from this!

Wheat and rye has a smaller kernel size and requires a mill adjustment to crush correctly.