450 Transfer aborted. Link to file server lost

I seem to keep getting this error whenever I try to uploading something thats too large.

It transfers fine for a few mins, then it stalls and eventually I get this error message.

Small files are fine since they don't take long to transfer, it just seems that I can't have a file transferring for too long.

I can actually get the damn file through but since I keep getting that error, I need to keep manually clicking on the transfer button. So it takes about 20 tries before I can finish a 30MB file. And I have a lot of files to transfer so thats very troublesome.

Does anyone know what the problem might be? I tried turning off the firewall and opening ports on my router but it still doesn't work. Using Cute FTP.

Thanks.

 

Do you know how to turn off PASV mode in Cute FTP 8?

I can't seem to find where it is...

Thanks.