Trouble Purchasing Army of the Czech Republic DLC (Steam)

[teh_ 1]

With some new money, I decided to purchase all of the existing DLCs for ARMA II as they were on sale. All of them downloaded and work properly except for Army of the Czech Republic. I was still charged for the purchase, but I do not own nor am I able to download it. Steam gives me the option to play it, and from there I am given an activation code to use in OA.

From here, I can't seem to locate where to activate it. Can anyone help me out here?

[FIXED]

Here's the solution. Thanks, Spades_Neil!

This doesn't work. Here's a real solution:

1. Close Steam

2. Run Steam as administrator.

3. After having purchased Armies of Czech Republic, launch Operation Arrowhead as you normally would.

4. An installation should appear.

5. There. It's fixed.

Seriously, I had to figure this out myself. Steam support doesn't know about this fix and there's no obvious threads here that explain how to fix it. There should be a sticky or something. I was getting close to demanding a refund.

Edited January 2, 2013 by teh_