When Ubuntuone executes it shows it's splash screen then for a moment another screen appears (unknown) and the splash screen replaces it again. I click on "I already have an account" but it appears nothing happens. (I have an account.) The same happens for "Join Now." When I click on "learn more" that does respond with the appropriate web page. I've uninstalled ubuntuone-installer, ubuntuone-control-panel and unbuntuone-control-panel-gtk and reinstalled them. Did the uninstall and removed the folder, reinstalled. Looked for a password in "passwords and keys." None for Ubuntuone. This works on android, windows other Ubuntu 11.10 boxes but not my Ubuntu 11.10 on my laptop. Where do I look for conflicts/corruption?
Found the answer myself. In case someone else gets this the problem was in the "passwords and encryption keys" wallet.
In the wallet under the "Passwords" tab there was an entry (not a folder) labeled "default." I deleted this. I had to reenter the key for my keyring and my mail passwords and all was fine. It did not delete my keys for signing/encrypting mail.
Then when I clicked on the Ubuntu one icon and clicked "I have an account" I was able to enter my Ubuntu one login/password. All is rosy now!
BTW this probably arose out out my rescuing my system some months ago. I have the /home folder on one HDD and the rest of the system on an SSD. I screwed up the system and reloaded it and just used the same home directory. I cleaned up most of the mess but apparently not this one. I had stopped using U1 and now just recently restarted using it.