Can't edit tags or rearrange elements

We have just upgraded our system to Omeka 2.03. In the upgraded version we are not able to change the name of tags or rearrange Dublin core elements. We followed the online instructions but the system is unresponsive. Is it an installation problem or a system bug.

Correction. After a reboot I can rearrange items and change the name of tags with one exception: I can't change the name of a tag that has a typo and unify it with the correct version that already exists as a tag. e.g. delete the space in Nτ'Αμπουάζ ( Pierre D'Amboise) in order to unify the tag with Nτ'Αμπουάζ (Pierre D'Amboise).
Thank you