[horde] Problem with TNEF after latest pear upgrade

[lst_hoe02 at kwsoft.de]

Hello,

on our testbed the following error is shown with latest updates when  
we try to open a mail with a "winmail.dat" attachment:

[Tue Jan 21 14:02:20 2014] [error] [client x.x.x.x] PHP Fatal error:   
__clone method called on non-object in  
/usr/share/php/Horde/Compress/Tnef.php on line 541

this prevents the mailbox from loading either by webclient or  
ActiveSync. Any idea how to debug?

Thanks

Andreas