Richard ~ The Alaska Tsunami Warning Center has good information on quakes. http://www.earthquake.usgs.gov/

It looks like they recorded your earthquake was 4.6
There was a 6.7 on the Aleutian Islands the other day. But, since hardly anyone lives there, I imagine only the sea lions got a "thrill".

If you click on the link to your earthquake, it gives you more info.

Earthquake Details
Magnitude 4.6
Date-Time Thursday, August 9, 2007 at 07:58:49 (UTC)
= Coordinated Universal Time
Thursday, August 9, 2007 at 12:58:49 AM
= local time at epicenter

Location 34.300°N, 118.620°W
Depth 7.5 km (4.7 miles)
Region GREATER LOS ANGELES AREA, CALIFORNIA
Distances 5 km (3 miles) NNW (343°) from Chatsworth, CA
11 km (7 miles) ENE (74°) from Simi Valley, CA
11 km (7 miles) N (353°) from Canoga Park, CA
44 km (27 miles) NW (309°) from Los Angeles Civic Center, CA

At the bottom is a link to "Did your feel it?" It asks you questions like: How would you best describe the ground shaking?
How would you best describe your reaction?
How did you respond?

Hmmm, don't see any questions about whether it was your birthday. But, I guess that could be the answer to all of the above questions.