I rebuilt all my BOs in the Business Object Mapper.  Rebuilt my BO project and then rebuilt the entire solution.  Problem stills exists.  Here's ALL the details.  This combobox had it's PopulationDataSourceSettings set to a method in a BO that I deleted from the BO's Data Retrieval Section.  So I cleared the PopulationDataSourceSettings for this combobox and now I'm trying to reset it to a new method in the same BO.  

Well, it sounds as though you are getting an error.  The DTE is bad about snuffing out errors (even legitmate ones).  The very first thing I would do is rebuild your solution, then go back into the form where you are having the issue and try again.  This would just ensure that all of your BOs are built.

The 1.6.5 beta should not be related to your issue here...so if this doesn't work then we will want to dig around a little bit more.

I'm trying to setup a combobox to be populated with a BO.  I set the PopulationType to BusinessObject and then try and set the PopulationDataSourceSettings.  The List Population Dialog displays for a second and then is replaced with a messagebox that says "Searching for Business Objects, Please wait...".  Well it never comes back.  The only way to get rid of it is to close VS.  When I reopen VS and try the same operation, the same problem keeps happening.  What's up???  I'm using the 1.6.5.0 beta.