Are you sure you're not placing an instance within itself? The only reports I've ever seen of this have been when people try to place an instance of libA/cellA/viewA into libA/cellA/viewA.
Even when I try that in 6.1.3.500.12b (the latest ISR), it doesn't crash - just doesn't let me do it.
So if you're really still seeing this, you should contact Cadence customer support.
Regards,
Andrew.