Thanks for your reply and attempts to help to date.
It may surprise you, but all of my projects start out as new, empty projects. I can't say if a new empty project has crashed or not, because I don't generally open and close same. The whole idea of Sequel is to create music, using audio and MIDI loops, isn't it? So as soon as you load a track with something, using Sequel as intended, the project is no longer empty. My issues usually start at some point during the adding and manipulation of tracks and content.
As my local support person has found, the problem with one of my project on hand to load, is repeatable on MAC and PC platforms to varying degrees. Does it take a rocket scientist to figure out that Sequel must be doing something to the project content to cause the crashes and dropouts? As tracks are altered and effects and inserts are added the problem seems to worsen. Just the other day I was just loading and listening to my recent projects, nothing else. I loaded them in random order. On loading the third project Sequel just sat there waiting forever after bringing up the track content. After closing (using Windows Task Manager to shut it down) and restating Sequel and going through the process again, loading different projects and listening to them, Sequel threw the message 'A Serious Problem........'
My local support person has sent the project and his findings to Steinberg engineers in Germany. It's now up to them to find the issue/s.
The point here is that THE LOCAL SUPPORT PERSON HERE IN AUSTRALIA HAS EXPERIENCED THE SAME PROBLEMS ON HIS PC AND MAC with my project loaded, repeatably. My project is nothing special, uses nothing but Steinberg content and features available in Sequel 3 and should in theory run without issues. But it doesn't.
It is now about 2 and a half months since I first bought Sequel 3. I have been messing around for a lot of my time during that period trying to find fault with my gear. MY gear is not faulty. I have run the software on several different systems with the same issues on all of them. They all have differing configurations, typical of most home user PC's, and exceed Steinbergs' recommended minimum system requirements. I am not spending any more time on fault finding Steinbergs' product. That is their responsibility.........I can send you my project if you like, or you can get it from the Yamaha support person here in Australia. Techsupport_MPD@gmx.yamaha.com
You have suggested (10 Oct 2013 post above) that the project Apps/Preferences file/folder getting corrupted is to blame. Why doesn't someone at Steinberg figure out why this happens?????? Why don't you find out why C000005 ACCESS VIOLATION errors occur. Why don't you find out why Sequel drops MIDI notes???? Why don't you find out why Sequel 3 .exe throws a 'R6205 - Pure virtual function call error' while you are at it??????? I have also had this happen on a couple of my PC's when Sequel is starting up (randomly of course!). Over to you to get all of these randomly occurring bugs and issues fixed along with Steinberg Germany developers. Good luck.