The generator matrix

1 0 X 1 0
X X X 1 1
X+1 1 X 0 0
0 X+1 1 0 0
0 X 0 0 0

generates a code of length 5 over Z2[X]/(X^2) who´s minimum homogenous weight is 2.

Homogenous weight enumerator: w(x)=1x^0+45x^2+210x^4+210x^6+45x^8+1x^10

The gray image is a linear code over GF(2) with n=10, k=9 and d=2.
As d=2 is an upper bound for linear (10,9,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 9.
This code was found by an older version of Heurico in 0 seconds.