Connecting 2 Modems via internal phone system

Hello There,

We are trying to link 2 computers using 2 Supraexpress 56i Pro modems (pci).
Both computers have win98 (1 is SE) and we are using HyperTerminal as our
connection manager (have set the emulation to ANSI).

Max Baud rate is set to 9600 and we are using Pulse Dial, all else is
Default.

Both modems appear to be calling ok but on answering seem to fallover ie the
answering modem starts by sounding correct (like the oscillating sound made
when connecting to the internet) but then goes into a series of tones that
alter the pitch in step changes. The calling modem then hangsup after
30seconds ie no answer and the receiving modem continues making it's whining
noise.

When calling directly to a telephone, the phone rings.

Any help would be greatly appreciated and if any further information is
required Please don't hesitate.

regards jake.