9.1 and 9.2 difference?

Hi, I have a function here

on LogMessage(FileMessage)
	tell application "Finder" to set LocalDrive to startup disk as string
	set FileHandle to (open for access(LocalDrive & "logfilename") with write permission)
	set EndOfFile to (get eof FileHandle)
	write FileMessage & return to FileHandle starting at (EndOfFile + 1)
	close access the FileHandle 
end LogMessage

This function works fine on OS 9.1, it just append the message to the logfile everytime it get called. But on OS 9.2 everytime i call this message i got a error message tell me “duplicate filename error” on line “open for access (localdrive & “logfilename”) with write permission”, seems like on OS 9.2 if the file already exist i can’t use this function. Anyone can help?
Yuan

Actually even 9.2.1 works fine, but 9.2.2 has problems
: Hi, I have a function here
: on LogMessage(FileMessage
: tell application “Finder” to set LocalDrive to startup disk as
: string
: set FileHandle to (open for access(LocalDrive & “logfilename”)
: with write permission)
: set EndOfFile to (get eof FileHandle)
: write FileMessage & return to FileHandle starting at (EndOfFile + 1)
: close access the FileHandle end LogMessage
: This function works fine on OS 9.1, it just append the message to the logfile
: everytime it get called. But on OS 9.2 everytime i call this message i got
: a error message tell me “duplicate filename error” on line
: “open for access (localdrive & “logfilename”) with
: write permission”, seems like on OS 9.2 if the file already exist i
: can’t use this function. Anyone can help?
: Yuan