I'm using Sibelius 4, Midi Yoke, VD:2, and Kontakt 2.  I've managed to solve all of my playback issues except for 2.

#1  There's a point in my score will playback always gets stuck.  All of the sound will stop except for a timpani roll, which will keep going until I hit the stop button.  If I start playback from a few bars before this point there's no problem.

#2  Occasionally during playback all my VD:2 sounds will cut out for a fraction of a second then come back in.  The hornline sounds, which aren't going through Kontakt, will keep playing.  If I watch Kontakt 2 while this is happening it indicates that it isn't receiving any midi information.

I have my latency set to 80ms.  I have a 1 gig of ram and a 2.6 ghz Pentium 4 processor.

Here's what I think the problem might be; I'm using the onboard sound on my motherboard.  At the moment, I don't have a soundcard for this computer.

How important is the soundcard?  Will buying one make a big difference?  How much do I need to spend?  Is 1 gig of ram adequate?

Thank you

Try setting your latency a little lower - around 40ms. 80ms isn't going to work too well. You might also try different options in the ";interface"; section of the VDL2 Soundcard setup window (if there are any). Read the sections of your VDL2 user guide pertaining to:

ASIO
MMX
Direct Sound

These are important concepts to understand when it comes to audio interfaces (soundcards).

It's never a bad idea to have a soundcard geared toward handling pro audio, but in a pinch you can get by without it. I'd suggest putting it on your wishlist. Check out the Audiophile 2496 (M-Audio) for a good entry level solution.