Celestron Barlow versus Celestron T-Mount Barlow

[philhas]

I noticed something odd tonight:confused:, I was trying out a new eyepiece (GSO 15mm Super Plossl) on Saturn, great views and a nice eyepeice for the price. Upped the mag with a Celestron 2x barlow (which I haven't used much) and things didn't look great, chucked in a Celestron T-mount barlow and it was so much better. the funny thing is the T-mount looks a bit cheap althought well built in comparison to the Barlow which was in the scope box when I bought it second hand. Looking at the barlow it has a noticable green coating to the lens where as the T-mount have a slight blue hue. Any thoughts apart from throw it in the bin!