1. The cell array id was wrong (was using InsertionId instead of Id)
2. We cannot use the vector::size to iterate as the size is not set, we should use this->NumberOfPoints

string was causing an error.
2.  k-d tree wasn't dividing space into enough regions (at least one per
processor) when the dataset was a very small test data set.  Now in
D3 we set the minimum number of cells allowed per spatial region to 2.
Normally D3 divides into enough regions so there is at least one spatial
region per process.

FIX; fix warnings for 64 bits platform, by upgrading to CVS (actually problem was fixed 15 months ago)