Have you had the printer running before or is this your first time setting up?
Make sure you set your IP on your nic card to user specified. Also make sure you set the IP on your printer (make sure they are different.) Then finally make sure you give the correct ip in Flexi for your printer. Im not an expert, but I am pretty sure thats all you have to do. I set my ip for example on my nic card to 72.72.72.73 and then the printer to 72.72.72.74 and made 72.72.72.74 the ip in flexi. Im running fine...