I believe I know what happening now, but knowing has not solved the problem. After Al (wxtech) was unable to ftp push to my site but had no problem pushing to his I started thinking the problem may be with my host.
I set up ImageSalsa to ftp push an image to Weather Underground and it worked great so my computer and network don't seem to be the problem.
My website is hosted with GoDaddy and I have the Linux/4GH plan. I called GoDaddy support and they could not find any reason it should not work since my other ftp programs are working. The only explanation they offered was that possibly ImageSalas's ftp was not compatible with the newest version of Apache web server they are using with the 4GH plan.
I'm not an expert in ftp so I don't know if that's possible or not. I do remember right after I upgraded to the 4GH plan the version of Filezilla I was using stopped working. When I called GoDaddy support they told me to upgrade to the latest version Filezilla, when I did everything started working again.
If it turns out that the problem is with IS's ftp compatibility with newer versions of Apache web server I guess the only solution is for Jason to update that part of the program. I submitted a support request yesterday on the website but have not heard anything.
Thanks to everyone who has helped me with this, especially Al. I like ImageSalsa and will continue to use it.
John