Try to use negative value in DT

Good morning,

I try to use negative value in design table to modify a planeposition (+10/-10)

But after closing the DT, the plane is on +10 or 0,
the value -10 doesn't work

I open the DT, and, indeed , the value -10 has been replaced by thevalue 0 !!!

what is wrong?
any ideas?

thanks

SW2009 - SP0.0 / XPSolidworksConfigurations design Tables