Hi,
It depends on how many connections your Checkpoint is already servicing?
If you bring up SmartView Monitor for your firewall, you should be able to see under 'General Info' the 'Concurrent Connections'. On my Checkpoint (R65), the default 'Maximum concurrent connections' is 25000, so how close is the 'Concurrent Connections' to 25000?
I am presuming that by adding a new STATIC NAT, you are exceeding 25000?
Also, What errors if any are you seeing in the system log through Voyager?
CheerZ and good luck