I'm missing the Tax submenu (inside of Sales) within the administration panel on my Magento 126.96.36.199 installation. I've an identical installation, which does show the sub menu. I've been through all the configurations I can think of, including the XML files in core/Mage/Tax, and I'm at a loss!
I've also reset the ACL list, incase there was something a miss there, as well as flushed the all of caches/indexes. I'm running the AccurateTax_Advanced plugin, on 3 installations, 2 of which work I don't have this issue with, so I don't believe it's causing any conflicts.
Has anyone encountered this issue before, or could they shed some light?
So, further investigation reveals that it is in fact the AccurateTax plugin that is causing an issue. Unless the entire plugin is removed, or it's disabled via the modules xml file (not the disable option given by the plugin in adminhtml), then the menu remains hidden.
Currently looking for a solution via AccurateTax themselves. A version mismatch may be responsible.