Question installation problem, please help.

I restored my backuped database tables last night after some mistakes. Then, my site was running normal.
This morning, I re-installed Kunena Forum(uninstall first then install). Then the problem happened: all of my components in backend administration menu disappeared, only the new kunena component is here...
I used FTP to check the directory of the components, they are all there.
Could anyone tell me what the problem is and how to fix it?
Thank you,

update:
After I copy the backuped jos_components table, the components in the admin has come back, and they are working well.
However, i just find out that my forum does not work well:
1: reply or new post goes to wrong categrary;
2, some categories have been duplicated many times.
I uninstall the forum and then re-install it, but the problem is still there.
how could i fix this?
Thank you in advance.

Sounds like possible data corruption. Why did you have to restore the database? What were the mistakes that caused the restore?

Thank you for your response.
The reason was that I installed joomlafish, then it caused a lot of problem for SEO(i do not have time to translate articles...). So i removed it. But some tables were still there, it requires manually delete. I think by mistake, i deleted some other important tables. This is why I have to restore my database.
IF the problem happened like you said, what i have to do to fix this?

When you restore a Joomla database, make sure you do so into a brand new and empty database. There are many auto id's on various tables and inserting data from a backup into an existing database with existing tables will cause severe data corruption because ids will get out of sync. You also must not restore portions of the database only for the same reason.

Great caution is to be exercised when you manually modify data inside a Joomla database. Once the ids are out of sync, no component install will go over easy as you might have a corrupted Joomla database to begin with.

There is little that can be done on the Kunena install part if the underlying database is impacted. Kunena, does not modify any Joomla tables other than the menu entry for itself to assign a logo in the backend.

Hope this helps!

fxstein

Thank you very much for your advice,
I will check it again.