Thanks for all the responses.
First of all ,to answer the safety issue, Yes, I use two straps to tie each side of the centre stand to the front wheel.
Woody grinding the bead. Great idea except I'm in Scotland. Regardless off the shipping costs, I'd be without my bike for quite a while. As Woody says, the bead is that large for a reason so I'd rather perfect getting the tyre off the rim as it is rather than reduce the safety of the rim - having the option of riding the last 40 miles home instead of fixing a puncture on the road does appeal to me. It has been suggested in this thread that pre 2005.5 bikes have a larger bead. My bike is an 04.
I've tried using WD40 but maybe not correctly. I would place the wheel under the sidestand and where the stand is pressing down on the tyre I'd squirt some WD40 between the rim and tyre. Maybe it cannot penetrate between the tyre and bead. Maybe I should try and squirt some in using a tyre lever before putting the wheel under the stand. That way it should get between the tyre and bead. I'll try again in the next couple of days and report back.