vB Error

[NjEcTiOn]

Database error in vBulletin 3.0.3:

Invalid SQL: SELECT whoviewed FROM thread WHERE threadid = 5
mysql error: Unknown column 'whoviewed' in 'field list']mysql error number: 1054

I recently reinstalled my vBulletin and I am getting this error when I start threads. Once a refresh the page though the database error disappears. What have I done wrong?

[pco]

whoviewed is a hack, check vb.org