I htink I got hacked

I think I got hacked or my "virtual dedicated" server may have been upgraded to php5 without my knowledge ....

i stayed in V2.5 and I think I have been hacked...

when I since yesterday when I click on a video this happens

ERROR: Unable to execute query

SELECT * FROM guest_info WHERE guest_ip=xx.xx.xxx.xxx' AND log_date='25-02-08'
Can't open file: 'guest_info.MYI' (errno: 145)

I updated to 2.6 and it is still happening ... any clue???