There seems to be a serious bug in your tag normalization implemented with the new version. The tags get eaten each time an article is saved. One or two characters at a time.

I downloaded and installed your update 2.6.4 today and directly activated tag normalization. That feature is too good to not use it. But alas, it seems to be responsible for cropping my tags. On every save of an article in the backend. After I deactivated the normalization nothing got cropped anymore. Now I just have to correct all the tags that were mutilated today.

I won't be able to give further comments to this error cause I'm going on vacation today.

I'm having this problem too, but only when editing/posting on the front end. The tags are there when I open the article on the front end, but when I click on save, the tags disappear. I find that if I go into the Administration panel and re-insert the tags, they stick. I agree that the Tag Normalization feature is good. Hopefully this bug gets squashed.