Issue with CF FTP

We have google base and a scheduled task in cf admin to output new entries posted on our site to a specific txt file. What a google simply does every night at a certain time is fetch this text file so it can update its database with the entries we updated the text files. It seems that every 2 weeks usually over the weekend we get a error report from CF with this message:

An exception occurred when performing the FTP putfile operation. The cause
of this exception was that: 553 jobs.txt: Permission denied on server. (Overwrite)

Code (markup):

Would anyone know why this happens? The weird thing is it works fine throughout the whole week.

 

Perhaps at that exact time the file on the FTP server is being written to causing a file lock?

 

Why on a certain day rather then everytime? It's set to be the same schedule everyday. This just started recently. This has been going on for a few months now, and no one has made any modifications.

 

I don't understand correctly. You say that google FTP's the file or you do? You error message seams to imply that you are FTPing a file to a location? Then from that location google scan it?

 

Basically what happens is theres a scheduled task for a cfm file which outputs the data on a txt file on the local server.

Then that file gets sent over to the google ftp through cfftp.

Then google just simply fetches that text file from its own ftp and uploads it to googlebase.

 

Then perhaps at exactly that moment google is reading and has locked the file?

 

Any idea why? It's the strangest thing, like this weekend it didn't happen.