[Brian]

Okay, I spent some time in our test lab and figured out what's going on here...

It turns out that the "include context" setting will automatically put an @ symbol at the start of the context. Presumably, this is meant to help differentiate the context from the action name, since iCal doesn't have a separate Context field for us to use.

In your case, since the context names actually start with an @, you end up with two of 'em when you export to iCal. I'm honestly a little surprised this wasn't uncovered/reported before, so thanks for letting us know about this!

I'll file a request against the iCal sync process. In theory, OmniFocus could check for context names like yours and not add the @ sign during export if one was there already.

In the meantime, though, the double @ signs may be unavoidable in iCal, unless the contexts are renamed in OmniFocus.

For what it's worth, I started off with my contexts named that way, but eventually removed the @ characters. Since OmniFocus has dedicated fields for action titles, project names, and contexts I found that I didn't need the extra character to remind me what was a context and what wasn't.