The ctm for the white glass addon is bugged, first of all when you make a wall bigger than 5x5 the default glass texture shows in the middle and expand as the wall of glass grows in size. Second, making a sideways t shape (in my testing) shows bits of black border instead of just white.

Confirmed both of them. They should be fixed now :)

Heres the download: http://adfly.mullak99.co.uk/q3I2b

Nope, still bugged and the glass wall thing is 3x3 and onwards now and the sideway's T thing is still bugged :(