I just bought myself a glass slide and thought i might try it out in a blues type solo.
I had already recorded a song in D minor, and solo'd in the usual D minor pentatonic. However when i then used the slide, still in the D minor pentatonic shape, it sounded completely wrong, why is this?
Is it my technique, or something to do with the intonation?

^Good place to start freepower. I had a slide and over looke this simple fact at first too. Your so used to frteting in the middle of the fret you forget to put the slide directly above the fret. If you arent doing this it would sound like the intonation is off.