[otrs] Some strange logs

Hi all, I've noticed many of these lines in my apache error_log file: [Mon Jun 16 10:16:18 2003] null: Use of uninitialized value in concatenation (.) or string at /opt/otrs//Kernel/Output/HTML/Generic.pm line 8 [Mon Jun 16 10:17:14 2003] null: Use of uninitialized value in concatenation (.) or string at /opt/otrs//Kernel/Output/HTML/Agent.pm line 591 What's the meaning of this? With regards, Alex P.s. Is it Martin's vocation time? No prompt responses from Martin anymore? ;-) I'm waiting for some answers for a weeks now.