Here is what I've discovered happens when I change a form that has already been distributed, then redistribute it: It creates a new distributed file with a distributed_001 appended to it. (i.e, if my PDF file is called filename.pdf, the first time I distributed it it created filename_distributed.pdf, and filename_responses.pdf... when I modify filename.pdf, then distribute it again, it creates two new files on my hard drive, filename_distributed_001.pdf and filename_responses_001.pdf.)
No problem if I'm distributing via email to new recipients. But here's my problem with this _001 file: I've already sent out an email, with a link to "filename_distributed.pdf" which is posted on a web site, for respondents to download and submit. If I post the modified file, filename_distributed_001.pdf, on the site, obviously the link in my email won't work.
I could just send another email with a link to this new _001 file name, but would prefer not to. So here's what my workaround has been. It looks like it will work with my tests, but if someone sees a big problem with this please let me know:
1. I logged into acrobat.com, and deleted "filename_distributed.pdf" (actually I renamed it in case the test didn't work and I could rename it back if so).
2. I then renamed filename_distributed_001.pdf to filename_distributed.pdf.
3. I then downloaded this renamed filename_distributed.pdf (which is "actually" filename_distributed_001.pdf, just with a different name) to my hard drive, to replace the file there (again renaming the file on my drive to allow recovery if this failed).
4. I then uploaded this file to the web site, replacing the file there.
So now if someone clicks the link in my email sent out, it pulls up this modified file because it has the right name. When they fill out the form and submit it, the responses go to the new filename_responses_001 file, which is fine, I can use that file to collect responses. I just have to merge them with the responses I've already collected in filename_responses.pdf.
If someone sees some problem with this, that I haven't detected yet, please let me know. Thanks.