Have a look at this thread
Adobe Reader XI 11 - Don't want prompt to send using EchoSign
Even though it's prompting for echosign, it's occuring in Reader.
Going by that linked thread this behaviour should no longer be occurring in the most recent version of Reader (as of Reader 11.0.10) though. You mention you have this version installed but double check this via help>about Adobe reader
Ok, the problem is resolved. I opened Adobe Reader and went to Help -> About Reader, and it said version 11.0.10. I decided to uninstall/reinstall anyways. When I went to Programs and Features, Adobe Reader in that list was listed as 11.0.07. I'm not sure how accurate that list is, but my guess is that something failed in the updating process. An uninstall/reinstall fixed the issue.