On 18.04.2011, at 15:49, Jorge Furtado wrote:

Both become mandatory if you enable this way, because you will not be able to create the ticket without fill these 2 items.

Usually, up to OTRS 3.0.7 and ITSM 3.0.2, the Service and SLA fields are optional, if you just enable the SysConfig option.
What else has been done / installed on your system to make them mandatory?

Cheers, Nils

-- 
Nils Leideck
http://webint.cryptonode.de / a Fractal project