Originally Posted by Bevdeforges

Unfortunately, that's exactly how US tax law works. You have to translate your sales and buying prices at the dates of the transaction - and given how the dollar has been falling, you wind up paying taxes on not only the euro gain or loss, but also the exchange gain (or loss).

I'm not familiar with the qualified business unit, but you may want to ask your tax accountant about it, just to be sure. I suspect that it would have to have been established before your sale of the stock to qualify for any special treatment, but it can't hurt to ask. You may also want to ask your tax accountant for advice about making future sales of your German stocks to avoid getting stung again.
Cheers,
Bev