Ciao!
It would appear to me that your efforts are in the right direction. It is interesting that I see all the CataBlog items and then the last two disappear. I presume they are suppose to be in the other tabs.
My first guess would be to try and put all the ShortCodes on one line with no spaces in between. This will ensure that there are no accidental paragraph or break tags in the HTML created by both plugins. If that does work I would consider installing my new plugin TRUEedit which can stop such WordPress filters as wpautop.
If that does not solve your problem I am curious about how exactly PostTab works and would like to look into it further with you. In particular I noticed that PostTab is splitting up the content after it is loaded with JavaScript, perhaps this is causing a conflict.
But Please first just try putting everything on the same line. Cheers!
- Zach