Try this, remove both. Restart Firefox. Any problem? Now install one add-on from its Mozilla Add-ons Web Page.

Restart. Any problem? Now do the other add-on.

FredMcD said

Try this, remove both. Restart Firefox. Any problem? Now install one add-on from its Mozilla Add-ons Web Page. Restart. Any problem? Now do the other add-on.

Thanks, Fred. Tried that and tried it again, restarting between attempts. No dice. Firefox still wants to download both every time. I can even apply my license to Download Helper. It runs while Firefox is open, but tries to reinstall DLH next time I open Firefox.

You can check the home page setting:

• Tools > Options > General > Startup: Home page

Firefox supports multiple home pages separated by '|' (pipe) symbols.

• https://support.mozilla.org/kb/How+to+set+the+home+page

You can check for problems with preferences.

• http://kb.mozillazine.org/Preferences_not_saved

OrangeBuzzard said

NoScript and Download Helper launch updates every time I open Firefox (latest ver). If I close browser, they launch again immediately.

Problem seems to have resolved itself. Related to a new scanning utility, but publisher denied being the cause. Thanks for the help folks!