I have run into the same problem and tried all the suggestions listed in the posts.

After a long night of trouble shooting I managed to get it to work one more time by doing:
- Upgrading SeaMonkey and then running the uninstall.
- Uninstalling the Harmony software.
- Removing all pointers to the Harmony software in the Reg.
- Reinstalling the Harmony software.

Then while using a new account to setup the remote I was able to run though the setup and program the remote. However when I tried to update the remote a few min latter it failed with the same error. Will have to give up on my laptop and try installing the software on my PC.

Has any one had any luck with Logitech support?