On a file opened with Random access Get and Put without position always work at
end of file and do not use the pointer position which was set with the
seek-statement.

To see this error use the following macros:
(1)
Sub Main
Dim iNumber As Integer
Dim aFile As String
Dim wert As string
aFile = "c:\daten.txt"
iNumber = Freefile
Open aFile For Random As #iNumber len=10
Put #iNumber, ,"AAAAAA"
Put #iNumber, ,"BBBBBB"
Put #iNumber, ,"CCCCCC"
Put #iNumber, ,"DDDDDD"
Put #iNumber, ,"EEEEEE"
Put #iNumber, ,"FFFFFF"
seek #iNumber,4
msgBox "loc()=" & loc(#iNumber)& " seek()=" & seek(#iNumber)
get #iNumber, ,wert
msgBox "wert=" & wert
msgBox "loc()=" & loc(#iNumber)& " seek()=" & seek(#iNumber)
Close #iNumber
End Sub

Then delete Seek-statement and use
    Get #iNumber,4,wert
instead of
    Get #iNumber, ,wert
Now you get the right record.

(2)
Sub Main
Dim iNumber As Integer
Dim aFile As String
Dim wert As string
aFile = "c:\data.txt"
iNumber = Freefile
Open aFile For Random As #iNumber len=10
Put #iNumber,1,"AAAAAA"
Put #iNumber,2,"BBBBBB"
Put #iNumber,3,"CCCCCC"
Put #iNumber,4,"DDDDDD"
Put #iNumber,5,"EEEEEE"
Put #iNumber,6,"FFFFFF"
seek #iNumber,4
put #iNumber,,"XXXXXX"
get #iNumber,4,wert
msgBox "wert 4=" & wert
get #iNumber,7,wert
msgBox "wert 7=" & wert
Close #iNumber
End Sub

Then delete Seek-statement and use
   Put #iNumber,4,"XXXXXX"
instead of
   Put #iNumber,,"XXXXXX"
Now it writes the data to the desired position.