Trying to purchase things in steam under wine 0.9.49 seems to fail for me… after you switch to firefox to sort out your purchase details it doesn’t want to return to steam to finalise the payment. Crossover office 6.2 trial was exactly the same – rather then switching to windows i got it working using steam installed on virtualbox (using the binary + guest additions) – remember to switch back to the wine steam for downloading your games though
