Your display will scale the signal to whatever its native resolution is (768p ?) and deinterlace the 480i to 480p as well. It has to. You might want to output a 480p signal to see which component deinterlaces the best.
Thx for the answer
ok...so no matter what my tv will always scale it to 1366x768 (HD ready). But why then put the dvd player to 1080i if the tv only will put it to 768? Are there any advantages to 1080i?
If you have a 1366x768 TV and an upconverting player, let your TV do the scaling (i.e., 480i or 480p output from your DVD player) unless the player's scaler is much better. Scaling the DVD to 1080i then rescaling back down to 1366x768 will cause significant detail loss.