German Corporations Donate to Romney

The German magazine Der Spiegel had a short article today saying that German corporations are predominantly donating to the Romney campaign; four years ago, the main recipient was the Obama campaign.

This year's figures so far, according to the US Center for Responsive Politics:

Deutsche Bank: US$86,250
Allianz Insurance: US$14,950

By comparison, the Obama campaign received:

From Siemens: US$17,355
From SAP: US$9,322

In the 2008 campaign, German corporations donated US$766,000 to Democrat candidates and US$612,000 to Republican.  In 2010, Deutsche Bank AG was the 6th-largest contributor to the Republican National Committee, with US$61,800.

I find this bizarre.  The numbers for the individual companies are comparatively small, but I'm still surprised they exist at all.  What's the corporate rationale?  And what happened to the ban on foreign donations.