Latest Chrome Portable can't install extensions

I've been using Chrome for a couple weeks now, and I just updated to the latest version (19.0.1084.56), and I'm finding that Google changed the procedure for installing extensions from the Chrome Web Store. I used to be able to click "Add to Chrome" on an extension I wanted to add. Now I see they save by default? Okay, so I saved it, and then tried to drag it onto Chrome. That doesn't work either, just prompts me to re-save it. I'm sure there's an easy solution I'm not seeing, because apparently nobody's asking about it here, or on Google yet. I see questions about how to save the .crx files, but not how to actually install them in the new Chrome version. The .crx file is only 15KB -- does that sound right? It's Weather Underground's (wunderground.com) full screen weather radar. It's a featured extension.

I see under Wrench > Tools > Extensions that I can "Load unpacked extension" under "Developer mode", but that doesn't work, either. It says it can't find the manifest file, or it's unreadable. Tried a few more, same thing.

Anything you/anyone can think of that would make it want to save the .crx file instead of installing it?

I have an extension that makes links open in focused tabs, as opposed to background tabs, but I've had it through a couple upgrades, and it hasn't prevented me from adding extensions before.

The last extension I installed was SearchO (context menu searching plus a search tool next to the Omnibar). Disabling that didn't help; prior to installing it I was able to install it.

The only change I've made since was changing my sync settings from encrypting only passwords to encrypting everything. (I don't know why I did it. Maybe because I use computers that are not my own (with permission) so for extra security.) I cannot change that back.