Database error when posting

[CaptainAwesome]

I was trying to do a test post on the forum today to see if something took and when i hit the "submit new thread" button i get the following error:

Database error in vBulletin 4.2.2:

Invalid SQL:

INSERT INTO postlog
(postid, useragent, ip, dateline)
VALUES
(7, 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36', 1205820656, 1402374984);

MySQL Error : Duplicate entry '7' for key 'PRIMARY'
Error Number : 1062
Request Date : Tuesday, June 10th 2014 @ 04:36:24 AM
Error Date : Tuesday, June 10th 2014 @ 04:36:24 AM
Script : http://<domain name removed>/forum/newthread.php?do=postthread&f=2
Referrer : http://<domain name removed>/forum/newthread.php?do=newthread&f=2
IP Address : <removed>
Username : <removed>
Classname : vB_Database
MySQL Version : 5.5.34-cll-lve


There is only 2 things i have done today to the site. I tried to import a database to my host so i could transfer the forum over but it would not import.

The other thing i did was reinstall this because my affiliate ID had changed. I didn't delete anything prior, i just re-uploaded it with the correct info:
https://vborg.vbsupport.ru/showthread.php?t=163393


Thinking it might be something i did today, I tried to roll back the site to a few days ago and its still happening.

When i go back to the site, the posts that generate this error are displayed.

Any suggestions? I would have thought rolling back the site and database to a few days ago would resolve this but no such luck. "Duplicate entry '7' for key 'PRIMARY' " doesn't mean much to me but i'm sure the pros here know exactly what it is.

Thanks