[Koha-devel] error-log => bug/warning

In the error log, there is a lot of the following warnings : Use of uninitialized value in string ne at /home/paul/koha.dev/koha/C4/Output.pm line 176, <KC> line 15. Use of uninitialized value in string eq at /home/paul/koha.dev/koha/C4/Output.pm line 182, <KC> line 15. How to solve it ? I think it's the array that's not defined. the problem is in 1.2 and main. -- Paul