Problem with delphi 1, dBase IV, TDBMemo

Hallo,
with Delphi 1 I have a Problem using a TDBMemo-Field under
dBase IV. Sometimes I got an errormessage like
 Memo-/BLOB-Datei fehlerhaft (It's the german version)
(it means korrupt Memo-/BLOB-File I think). I don't have
any idea to prevent this error.
I try a small programm in C++-Builder, but with the same
result.
Any help would be greatly appreciated.
Juergen K.