Many home replacements are a bit buggy and, after you make certain changes, might get stuck in a loop where they keep FCing over and over again until you (hopefully) find a way out of it or end up recovering a backup or factory reset. It's happened to me twice now (with Helix) and I've found a way to recover without using a backup that wasn't well documented anywhere.
The most commonly suggested solutions ignore the full scope of the problem. 1) You aren't prompted to choose which home app to use once you've chosen a default. 2) You can't launch any apps because your home replacement isn't working. 3) You can't "Clear Defaults" for the app because you can't get in to settings. 4) You can't uninstall because you can't get to Manage Applications.
So.. here's how to do it.
* After the FC, click on "Report" so you are given control again
* Push the Search soft button and search for anything, just to get you in to the browser
* Find a place to download a home replacement APK. (Try here: ZeamCustom.apk)
* When it's finished downloading, click Install
** You'll have to have alternate application sources enabled to install an APK without using the market. If you have it disabled, you'll be prompted to enable it
* After it's installed, click the Home button. It should ask you which app to use, choose anything but the replacement app causing you problems
* Uninstall the app, and if you know what change caused it, you can reinstall and make sure you don't make that change again