Oil - No Oil

Last night while driving my 06 Subaru Forrester (41K miles), the check engine light came on and the cruise control light started blinking. The oil light did not come on. I pulled over and in checking among other things the oil level, the dip stick was completely dry. I added 2 quarts of oil and it was still registering dry, but the check engine and cruise lights were no longer illuminated when I started it. The next morning, the dip stick showed that I had too much oil (my guess is that it was at least a quart above the high mark). The next day I took it to the dealer and when they checked the oil level, it was again not registering on the dip stick. The code indicated that there was no oil in the left and right something-or-others. At no time while driving the car did it behave oddly. There are no indications of oil usage under the car or on the garage floor. They believe that I drove the engine dry of oil. I believe that something's clogging the dip stick tube. It's been roughly 4K miles since the last oil change. Any ideas??