The markup that VS is generating is fine, it's your DOCTYPE that's
incorrect.  Your DOCTYPE indicates you are writing HTML 4.01 Transitional,
where the trailing slash is illegal, but VS generates XHTML 1.0 (and places
that DOCTYPE into the code), where the trailing slash is required on tags
that don't normally get closed.

You can either leave VS's generated DOCTYPE tag alone (not change it to HTML
4.01) or you can manually change your code to be compliant with HTML 4.01.
I'd suggest you simply let VS generate the XHTML as it does by default.

-Scott