Subscribers can't log in but WE can log in with their user name / pw

This is about as strange as it gets.

The last two subscribers couldn't log in despite changing the password for them to something really simple.

However, WE can log in with their credentials just fine.

What could possibly cause this? They get a user name / password error but we can't reproduce it.

Thanks,

Christine

Also, we have made NO changes at all, I've been using the "free" module with coupons and it worked fine until a week or so ago.

I just checked the protect plugins and here's what we have checked:

htpasswd
new_rewrite
php_include

Should we uncheck one or more?

Thanks,

Christine

Thanks. I had some communications with both subscribers and they use Win 7 with IE 8 or 9. And that works fine on our computers. I sent them links that explain how to clear the browser cache and disable proxy, but they're both very new to computers and may not be able to figure that out.

So I hope I can get them to install Firefox.

I've searched the web and couldn't find anybody else with that problem and it sure is weird that our last two subscribers can't log in. I'll update here once I know more.