to reproduce this bug:
1. Add Blogs Portlet
2. Click "Add Blog Entry" button
3. Fill required data in blogs entry
4. Enter some tags separated with comma (like "blog1, blog2")
5. DO NOT PRESS "Add Tags"
6. Press "Publish"
Forms is submitted, before submit I can see what tags was parsed and added into tags control as 2 separate tags, but tags are not submitted, bloge entry created without any tags
Bug is not reproduced is only one tag entered (without comma), as well as everything works well if "Add Tags" was pressed before submit.
Reproduced with other assets used tags (wiki for example)