Setting a static IP address on the box in the same sort of range that other devices on your network use can cause IP conflicts for other devices as the router doesn't know that x.x.x.12 is supposed to be reserved.
If you want to set them at the box end it is advisable to use the top end of the range.
Most routers do DHCP from 192.168.1.2 right up to 192.168.1.254 (or 255) The router will start allocating IP addressed from .2 when it hits .10, if your box has not announced it's self on the network yet, the router can give the next requested device .10 and there is then an IP conflict.
By setting your boxes IP address to the top end of the range will avoid this. On the above example I would use 192.168.1.150 and 192.168.1.160 which keeps them away from everything else and each other.
As gmangt4 has done, it is best to give static IPs from the router. I have never tried gman, but think you can spoof the MAC directly on the box, but if you are up and running, why fix it to break again lol