Nero - closes when in the middle of editing a movie

I recently installed Nero on my Sony with Windows Media Center 2004 (contains all the latest patches) and 2g of memory as well as at least 50g Free harddrisk space. I purchased the Nero 6.3 version with a dvd writer and decided to use Nero on a different computer instead so I needed to purchase the NERO 6.3 online with a dowloaded serial number (so I could burn to my dvd drive since the bundled version doesn’t allow you to use a different dvd drives). I then entered the new serial number and dowloaded the updates for
Seems to be working fine except for when I am editing a movie (to take out commercials)…it keeps closing on me with no warning or error message. I have no other programs running and CPU utilization is low when it happens. If I edit again it usually works…but sometimes it happens a few times in a row.
Right now I am just constantly saving my work…but it is getting very frustrating.
Anyone have any insight to this issue ?
Appreciate any assistance !