Thanks for all your comments and advice.
First a few short answers:
Di Pro = Dimension Pro synth plugin, (sorry I used the abbreviation I have seen it used on here before but can understand full details always help in trouble shooting issues).
Bob - that check box was ticked on signature not sure why system specs didn't appear, but it did appear on my last post when I went and copied and pasted them (?!!)
Great tip - I managed to load old project into X2 using shift, (got some pop up boxes and said 'ok' to them but nothing really looked like 'safe mode'. I'll now try disabling all plugins and switching on one at a time and see which one stops it loading...
Not 'trolling' whatever that means - I just hit a wall of frustration, (which I'm sure we have all had at some time or another!)
My point about Logic vs Sonar was that it just worked, I used it for years on a PC and did end up using 5.5 on a PC with XP, (this is still on my old computer and I still use it from time to time and is very stable).
I agree that probably most of my problems could be Windows/PC related, (I will update all chipset, Bios etc after Xmas), but that was partly my original point - perhaps if I'd invested in my first ever Mac with Logic I wouldn't be having these issues all the time? Also I haven't been that impressed with M-Audio soundcard and have been thinking of switching to Motu...
I get the point that Apple haven't really done much to Logic over the years and are slow to update it as well with 'sexy' new features, but maybe Cakewalk should learn from this a bit. I get seduced with the constant new gizmos which will improve my projects and creativity, but then end up spending ages troubleshooting the side effects or installing patches/updates
Bottom line is I want to spend my time composing and recording - not trawling the internet for solutions to problems.
When it works Sonar is amazing and sounds great - just messes with my head and leads me away from creativity and into technical support too often!
Thanks for all your advice - Merry Christmas!