DNS Problems

We have had ongoing issues with DNS. the problem in this: a handful of computers on the network do not resolve correctly to the right ip address. For instance, if I ping a workstation name it will reply back with an ip address. If I do an NBTSTAT -A to that ip address it's showing me a different workstation. If I then ping that workstation it also resolves to the same ip address as the first workstation:

Example:

Ping ws187

Reply from 10.0.0.96

Ping ws194

Reply from 10.0.0.96

Only one is correct (in this case ws187) cuz when I do an NBTSTAT -A on the .96 address it shows up as WS187.

I have no clue as to the true ip adress of WS194 cuz I don't know where in the office it is offhand.

We run spiceworks to do inventories and it is messing it up.

These are all on class c network and all dhcp.

Any clues???

By the way, it's not always the same computers that have the problem. It varies week to week.