[TYPO3-seminars] Unable to autoload class "pear"

[Daniel Doesburg | Doesburg.biz]

Hi,

I've installed the seminar extension. And all went well until I tried to 
set up the frontend editing.
 From that moment I get hundredsw of messages: Unable to autoload class 
"pear"

Who can tell me what it is and what I can do to solve it.
For that same reason (it think) I get a timeout on the database in the 
frontend editing.

Kind regards,

Daniel Doesburg