Thanks - bit of a streak at the moment but this will flatten out over time.

Karla prices do vary - Bookies don't hold much on WTA so easier to move the odds. Karantacheva was available at $1.67 @ Ladbrokes and elsewhere for quite a few hours so it's more the timing of when you're checking prices and how the market moves. prices will sometimes drift the other way - like Haynes yesterday.
The bets suggested today will all drift in my opinion so get in early. Kirilenko will definitely shorten as will DiazOlivia.

Sparks - don't handicap the ATP - I find it takes enough time to compile my database and run my programs just doing the WTA. Prefer to specialise.