Boggled by bodies....

I am trialing SW2010 SP2.1 here at home, and I have come across this strange phenomena - 4 bodies within the weldment have merged (2x structural members and 2x boss extrudes)  into 1 body, mucking up my cut list!!!!

Any ideas why  this is happening? part attached for anyone who wants to check how it has happened

Most bizarre!

SolidworksWeldments