Songs Sound Different When Exported

[thephatboi]

Ok, I am going to be another "conspiracy theory" advocate. I am a very experienced PT HD user (HD3 7.4.xx, OSX 10.4.9, G5 dual 2gig) and I when I run out of dsp I sometimes want to record a track or two with all the plugins and effects on it to another track or bounce to disk and re-import, then shut off the original track to create some new processing power. I am sorry but I ALWAYS hear a difference between the original "live" running track with plugs and fx and the new recorded to new track or bounced/imported track. The new tracks always sound like they lost something, very subtle but non-engineers can hear it. I am of course very sure that no sample rate conversion or dithering is going on. This is really a problem for me and would like to hear if others have this prob and from Digi, is this just an issue with going through a bus changing the sound ever so slightly??? I think so, call me a heretic but I hear it and i am not a wanker. Looking forward to hearing more about this...any work arounds?? Should I dig out my dat player and record to it (being sarcastic but what's up with this?) Thanks in advance.