Mozilla issued this statement on their add-ons blog earlier today in light of the issues with TMP and Firefox 17,
The popular Tab Mix Plus extension is causing some problems for users in Firefox 17. The problems include broken menu items – like the one that opens the Add-ons Manager – and broken links in Firefox windows, like the About dialog.
This extension broke due to bug 761723, and a fixed version hasn’t been released to AMO yet. Apparently there’s a development version of Tab Mix Plus that fixes these issues, so hopefully it will be pushed to the general public soon.
In the meantime, we recommend users to disable the add-on until the new update is released.