Boy is this a hot potatoe :) I will give it one more whirl as well as upgrade Mediaplayer. My experience of audio comes from my time with CreativeLabs - so mostly it's a little dated.
Thanx guys for the help and suggestions :0) History and conclusions - probably mistaken but conclusions nontheless.
Microsoft's Mediaplayer is designed to work with all the other services in Windows and so far I've never had a crash using it.
RealPlayer has a nasty habit of messing up several VxD functions in particular video. Hence the numerous 'page faults' also grabbing resources which the makers assume are free but are not, hence 'illegal operation'. So which resources? - 1 memory 2 irq 3 very rare dma. Memory grabbing - writing or trying to write to a000-ffff. Assuming that the sound card is on irq 5 when it is not and something else is. (Windows auto relocates IRQs as a Motherboard BIOS requires! Service name 'Configuration Manager' Registry Key/s 'Enum')
Files which Windows identifies as the problem PNEN.DLL - 9 times out of 10. Occasionaly realplay.exe.
Was RealAudio ready for release? I wonder.