I had my fridge out for fan maintenance.  http://www.snurl.com/vanagon
(http included for browser com-pliance)  I tried the let it rest upside
down for several days, maybe a week.  I didn't shake it or rock it during
this time.  I saw no benefit from this.  Before and after my fridge has
trouble when ambient temps are up there.  Can only drop about 35 degrees
below ambient.

Edward