I hate to be a bother, but I have never used an ftp client before. When I use your url, I get this window (see attached) showing a list of other folders but there is no way for me to add my folder to it.

I am trying to send you the stack in question, but I am unable to find ftp directions on the url you suggested.

I just downloaded v 4.2.7 and each time I try to use it on a stack I get a message "order of images is not consistent". The resulting combined image is just digital snow. These are image stacks that previously I successfully merged with v 4.2.3. I just re-did them again with v4.2.3 with no problems ...