+1 to all of the above. One thing I did not see mentioned: What was your fermentation temperature? Anything greater than about 68 F can cause fusels that have a tendency to kill head. So keep fermentation temperatures down to improve head as well.
+1 - no amount of cara-pils or wheat can save the head on a beer fermented too warm, not to mention the other nasty flavors that come along with fermentation temps that are out of the range, or un healthy picthes of yeast. Use the pitching calc at www.mrmalty.com to get an idea how much yeast you need to pitch. A good fermentation is the key to great beer, including great head!
How do you explain the Belgium beers, some fermented in the 80's, all with the famous rocky head and Belgium lace?