Oh, sorry, did not know this was their mobile workstation line. Makes sense, then.
To be honest, considering we're talking about Dell, I must say I'm nearly surprised they did not put a DRM in the BIOS/UEFI to forbid using more than the quantity the laptop shipped from without paying a license. I assume it's that then, all the customers that do buy the cheap lines and update the RAM themselves would go to other shops ?