[imp] Error after upgrading IMP

[Marco Maiani]

I've upgraded Imp from 4.0.1 to 4.0.4 on horde 3.0.6

After the upgrade, when I try to read or to compose any e-mails I have 
this error. The line on mime_drivers.php seems to be about xlhtml but 
the emails haven't any xls file attached

"Parse error: parse error, unexpected T_CONSTANT_ENCAPSED_STRING, 
expecting ')' in /usr/share/horde3/config/mime_drivers.php on line 298"

have somebody any idea about to fix it?

Thanks

Marco