Import of dBase memo field drops every 48th character
Import dBase IV .dbf (and .dbt) data into a Filemaker Text field. Filemaker does not transfer characters from Memo fields; 48th, 96th. (etc? unknown)
Export the text from dBase to a delimited file. Import the delimited file. Perfect results.
Sounds like an issue reported previously.
For More Information see: Bug importing dBase data into File Maker Pro 10 Demo (OSX)
This is one of many acknowledged bugs that can be found in the Known Bug List here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html