What happens, apparently, is that there is an ally plug that screws into the end of the crankshaft to seal the crank oilway. It can start to unscrew itself through vibration or whatever and as it does the soft ally gets lathed away by the harder outer races on the crank bearings. Eventually, the plug gets worn so thin that it drops out or pops out under the pressure of the oil and then all the oil just gushes out back into the sump without going through the crank or conrod oilways.
There are write up about it on
http://www.moto-one.com.au/performance under the ST2 hi-comp thread and the 888 thread
The cure is simply to use that blue loctite (?) or whatever it is you use when you never want to unscrew the part again, trouble is the crankcases have to be split to do it.
Nelly or someone who really knows what they're on about might be along in a minute
[Edited on 16-2-2006 by Jools]