Vista - UAC Prompt, interrupt or background

I notice that in more recent builds of Vista, launching our app will no
longer interrupt the user with a UAC elevation prompt. Instead, a task bar
item will flash. Clicking on that taskbar item will then bring up the
prompt. I think this is MS' way of making UAC prompts for "non critical"
apps less intrusive.

My question is, is there a way to force the UAC prompt to interrupt the
user? Is this a setting in the app's manifest file? I'm not having any luck
locating an answer. Thanks.