Slow starting 2ltr diesel Symbol

Heres a story for all the Peugeot 2ltr diesel engine owners.
ever since we have had our Symbol, April '11, I have had an occasional
problem starting the engine. It would spin at first but if it
didn't start immediately it would churn veeerrryyy slowly for around
20/30 seconds and then start with a cloud of smoke. It got worse
over the last 2 weeks tour of Scotland. The battery was new in October
2010 so I went to Halfords to get it tested. No problem with the battery
the man said, let's test the alternator. When I started it he said he could
see the problem. The alternator voltage was down but more importantly
he had seen a shower of sparks from low down on the engine. He started the engine
and lo! sparks were falling from under the gearbox. It was the bonding strap
that connects the body to the engine. All the starting and charging current goes
through this strap and mine had corroded at the gearbox end. I got it home and
contacted the service garage who told me to bring it in. Now of course I couldn't get
the beast to even turn over. The head of the fixing bolt had corroded/arc'd off.
Eventually got it to the fitter who told me they always torque the bolt on PDI
as "it is a common Peugeot problem"! Tightness is not the problem, mine was tight.
A better solution would be to take the strap off, clean it and refit it. I've not
heard of anyone else having this problem but you never know.....
We have a 2003 Symbol with 33k miles.