Thank you Procyon - I use this programme to create my pre recorded radio programme - I put two hours worth of music actually 1 hr40mins then I record and drop the introductions for the radio between each track then export it as one track. I think I understand what you mean - all that now seems to cause the problem. Thought it time to move on so I have now got Audio Cleaning Lab 2013.
Yeah....applying enhancements to nearly two hours of audio in real-time would probably choke any computer system. I'd be better to break it down into bite-sized chunks (steps).