Is this really changing the destination IP, or just the source IP. Are there multiple connection possible?

That would change the destination address, not the source. For example if the inside client requested 1.1.1.1 it would be translated to 2.2.2.2.

static (outside,inside) 1.1.1.1 2.2.2.2 netmask 255.255.255.255

OK, thats what I have tried. Maybe there is an routing issue on the Outside network.

Clients 10.42.2.25 to Server 192.168.249.25

The output says translating inside source to outside destination, and untranslating inside destination to outside destination!

850: ICMP echo-request: translating inside:10.144.4.1/1832 to outside:192.168.249.25/10

851: ICMP echo-request: untranslating inside:10.42.2.25 to outside:192.168.249.25