Can't get Kindle app to sync with new Ipad

I have new Ipad and have two original Ipads and a Touch synced to Kindle. I think my problem comes from restoring this new one to the original one but then changing its name since I'm keeping the old one. Kindle only has the two Ipad ones and doesn't "see" this one. I sort of think it is like Kindle tries to connect with Diane's Ipad but when it does this one says 'nope, I'm Diane's Ipad 3". I was in chat with Kindle specialist and couldn't resolve it but then he wrote me and says I need to deregister this (Ipad 3), delete Kindle app and then reinstall app and reregister it. I'm a bit nervous about losing reading on Ipad one since I'm in middle of a book and then it taking ages to resolve this,

Soooo---is anyone hAving similar issue? How did you handle it? One of the Ipad ones is my husband's (David's Ipad) so that shouldn't be affected.

Resolved. i deregistered the new Ipad and reregistered it and downloaded the books I wanted on the device from the Cloud. Like the upgrade to Kindle app from the morning (16th). The old Ipad was also deregistered but I just reregistered it and all is well. The third one which is my husband's with different name didn't need anything done,