I've looked everywhere for the answer to this one but I mostly find discussions on duplicate calendar items and contacts. These are fine on my iPad but every Reminder I have is duplicated. I use iOS5 with an iPad 1. I have an iPhone 4 as well.
Thanks.

Check icloud.com on the computer and see if they are single there. If they are try turning off Reminders in Settings > iCloud. Choose the delete from iPad option. Check the Reminders app to make sure they are all gone, then turn them back on.

Same thing on the iPhone if they are doubled there as well.

If that does not work, signing completely out of, then back into iCloud might help. When you sign out of Settings > iCloud make sure iCloud also disappears under the Settings > Mail, Contacts, Calendars > Accounts area. if not, delete that account.

that seems to have done the trick. Much thanks.
They were not doubled on the website nor the iphone. Any idea how this happens?

When first setting up iCloud some people accidentally ended up with the account set up twice. At least that is my theory. I'm not sure exactly how, but since the iCloud account shows up both in Accounts and in iCloud's settings it's hard to tell it has happened.

Or it could just be a glitch. They happen, and iCloud is new enough that there are bound to be some glitches (bugs).