Heidi and Spencer stay in seperate hotel rooms in Vegas

Awww... the dynamic duo is having relationship problems.

Heidi Montag and Spencer Pratt are in Las Vegas. Same city. Seperate hotels. Heidi is staying at the Palazzo while Spencer is checked in at the Hard Rock.

Their rep says "yes it's true, they're working on their relationship." But then again, they're taping The Hills while in Vegas so who knows what's real... and frankly... who cares.

If things go terribly sour and they break-up, at least Heidi has her amazing singing career... and Spencer has his wicked videotaping skill. The world is theirs, we're just renting air.

PS -- You could park a Mini-Cooper in horseface's mouth in this picture! She's awwweesssoooommmmeee!!!