I write a new post (A). All is fine and the tags are working.
I write a new post (B). All is fine and the tags are working for this post, but tags for A disappear. Only the front page is affected. tags still exists on edit.
The tags are only displayed at the first post of each page (index, search, archive, ...). On all other post of the page no tags will be displayed although there are tags defined.
When I edit the post the tags are corretly shown in the tag-field. On the single-post-site (with the comments) the tags are also correctly displayed.