This is an issue with PowerBook 280c's that have version 1.5 of the Express Modem software and extra RAM installed.
The solution is to upgrade the Express Modem software to 1.5.2. This problem was addressed in the 1.5.2 version of that software.
To locate software updates mentioned in this article please refer to the following Tech Info Library articles:
Where to Find Apple Software Updates
Obtaining Apple Product Support in the USA
Article Change History:
08 Nov 1994 - Reviewed.
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