Often the only way to find this out is to call the manufacturer of your modem and ask. If your MLS is a Maestro System or Master System, you may have to upgrade your modem to a model which provides true hardware error correction. Most RPI modems are older, slower models and have compatibility problems with many other kinds of software. If you buy a new modem you are unlikely to get stuck with an RPI modem. The best solution is to disable your sound driver while running PC Access, or upgrade to a sound card.
Some computers are unable to receive characters from a modem while simultaneously writing to disk.
On such a computer you should try disabling the scroll back on the Defaults Setup window. If you only have communication problems while you print a host report, see Dropped Characters while Printing Host Reports . If not, help us improve it .