Can anyone give any help?

I realise this has probably been posted before so Apologises

What's absolute best way of converting AVI/SCVD mpeg to DVD?

At the moment I'm using Ulead DVD workshop 2 to convert and Author my AVI/MPEG collection to DVD with menus. If there is any playback issues with the files in the Ulead preview then I mess with the files with TMPGENC, Virtual DUB AVI version and the MPEG mod version.

All was going ok until I starting converting some of my new clips, the files are fine before putting them into Ulead but when they come out as the complete DVD as VOB's the audio is so out of sync its unreal. My pc is left on overnight with just Ulead running and nothing else, its a P4 with tons of power and space so can't be that.

Can I use anther encoding package to convert the files to DVD mpeg then just let Ulead convert to VOB?

I've not installed any new codec's or software on my system recently so don't understand why they new clips are coming out like this.

Any ideas?