Hi Devan,
Example 31 is probably the best for various lookups etc. I've tried there, and I'm not seeing the popup close on enter.
Type updating an invoice Linitem - select a product and press enter. In FF an IE here, nothing happens. (indeed the enter is completely ignored.)
Now I agree, it would be nice if the Select button was the default button there (and that's something I can look into) but first I think I need to figure out why, for you, the browse is closing.
Cheers
Bruce