I just bought a Windows Vista Home Premium desktop to do my writing with. When using VDL the notes either get cut short or they dont play the rhythms in time at points when its playing back. Anyone know how to fix this? I have Horns and VDL instruments loaded on the same score as well if that helps.
Thanks,
Tracy Roberts 

I'm not sure what version of Sibelius you're using, but assuming you're on version 5 or later, have you spent any time optimizing your settings in the Audio Engine Options window? If not, this will be a good time to get more familiar with your soundcard, and its accompanying drivers. Hopefully you're using an soundcard with ASIO driver support.

Here's a good FAQ to check out.
https://www.tapspace.com/support/faq/index.php?sid=1953558&lang=en&action=artikel&cat=4&id=33

There's a good chance that adjusting your buffer settings, and ensuring you're using an ASIO driver (if your soundcard supports it), will help optimize playback performance.

Ram is 4.0 GB
Processor is AMD Phenom(tm) 9150e Quad-Core Processor 1.80 GHz
The Model is a6700y
System type is 64-bit Operating System
Its a new computer I just bought it last week. And Zach Sammuel says hi.

Tracy,

Thanks for the info on Sibelius. It'll also be helpful to know some specs on your system (RAM, CPU, processor type, etc), as well as how you've configured the audio settings within your notation program.

Im using Sibelius.

Are you using Sibelius or Finale?

Also, a breakdown of your system specifications would be helpful as well (see my signature for an example).