Excel file open problem when iCloud 2.x is installed

Sometimes users get a error message when they try to open a .xlsx file with Excel 2007 oder 2010.
The error message is like

"Excel found unreadable content in 'xxxxxx.xlsx'. Do you want to restore the content of this file? ...."

or in german:

"Von Excel wurde unlesbarer Inhalt in 'xxx.xlsx' gefunden. Möchten Sie den Inhalt dieser Arbeitsmappe wiederherstellen?

The funny thing is:

- When you have excel closed and double click the .xlsx file in Explorer it opens without a problem
- Also when you open it via the recently used files

- But when you open it via the file menu of Excel then it shows that error
- And then all other open requests show the same problem, until you restart excel


The cause of this problem is Apple iCloud in Versions 2.x and up.
So you have to remove the iCloud 2.x stuff and the problem is solved.
You can use iCloud 1.x, this gives no problems, just make sure you disable autoupdate for that thing...

Just wondering what the hell apple is doing there at them moment I try to open a excel file....


Some references:

https://discussions.apple.com/thread/4508650?start=0&tstart=0
http://www.office-loesung.de/ftopic550332_0_0_asc.php