We have recently upgrded from 1.8 to 1.9 and installed nwiki
When working with a wiki imported from 1.8 constructed in the html editor
the tags caused a lot of problems adding a tag to one page overwrote the other pages.
However when working with a nwiki or dfwiki created from scratch no problems.
Not sure why but it would have saved a lot of time sorting out how the tagging system works if we realised it earlier!
Other points it took a while to figure out
- It was also not clear that tags work across multiple wikis
- that there is a difference between the tag block (which "administers" tags)
- and the wiki-tags block (which links to them).