If the components on the modem overheat then this can cause spurious results. If the modem is an internal one and you suspect heating problems within the case, look here . If power management features are being used, they need to be set very carefully to ensure that they don't kick in during a download and disrupt the modem. If you have only been trying the connection with one remote host, try another one. The problem could very easily be with the host at the other end of the connection.
Problems there can range from overloading to incorrectly-configured server software.
Electrical storms and other severe weather can interfere with modem operation by causing intermittent line noise. Don't be surprised if you have disconnections if using a modem during one of these storms. Note that a surge suppressor with modem protection will not help with this, as it only provides protection against a strong surge that could damage the modem. It won't clear noise from the line. This page has been served 8416 times.