KDE 4.10.2 - Embedded email URLS not opening in browser - issue

This may/may not be related to issues detailed HERE relative to KDM Theme and Activity icons.

I updated to KDE 4.10.2 yesterday (from 12.2/4.10.1)

In addition to the sort of ugly KDM Greeter theme issue,
I find today an interesting issue I can’t seem to resolve:

When I read an email (I happen to use Thunderbird) and click on an embedded URL, Calibre opens, not a new tab in Firefox.
I checked System Settings-Default Applications-Web Browser and it is still set to Firefox.

I am running Thunderbird 17.0.4, which installed (updated) 3/18/2013 and I am (almost) positive I have clicked thru URLs in emails since then, so I remain a bit suspicious of KDE 4.10.2.

Anyone else seeing this?
Suggestions?

I did check some Libre Office files I have with embedded URLs, they still open in Firefox correctly (using the ctl-click method).

Well, I don’t use Thunderbird, but maybe this helps:
http://forum.kde.org/viewtopic.php?f=63&t=102591

I’d also suggest you check the settings for html in System Settings->File Associations (search for “htm” there).
System Settings/File Associations - KDE UserBase Wiki

Thanks, “File Associations” seems to have corrected it