Default Exchange - decode mail not possible

Still having problems with the Exchange Mail Account since the 4.3 update: I'm not able to read my incoming mails, only the subject text is readable. The main content of the mail is empty, there is a message "not able to decode the mail". New installation doesn't resolve this (wiping cache either). Firmware 4.3 10.4.B.0.569 DE Telekom (with Commercial & Journalist it is the same). Before updating there weren't any problems.

PS: Exchange calendar sync works well; sending mails too.