Contradiction between CAS and Home

[COB160]

In CAS mode if I type
(1-e^(-1/2))/(1-e^-2)
the result is
(e^(1/2))^3/((e^(1/2))^3+(e^(1/2))^2+(e^(1/2))+1)
wich is 0.174326466693

In home mode if I type the same
(1-e^(-1/2))/(1-e^-2)
the result is
0.455054233923 that is the result I was looking for.

How can this be possible?