Pleaseee... Helpppp.... !!!

I am using SCO Open Server 5.05. Recently, i have upgraded the system which means transfer all apps and data to the new system. Everything work well except one thing. On my old system i have an external modem which to dial out. Now that i use the same modem on the new system which doesn't seems to work..... Everytime i tried to dial out.... All i got is " CAN NOT OPEN MODEM ". What could be the problem ? And how should I correct this problem... Pleaseee Helpppp....

Thank you so much for you time