phpbb forum timeouts

Did anyone encounter and managed to solve the problem with phpbb which a client of mine at JH is having: When opening a thread it won’t load but after ~5 minutes reply with
"Could not obtain topic watch information

DEBUG MODE

SQL Error : 2013 Lost connection to MySQL server during query

SELECT topic_id FROM phpbb_topics_watch WHERE topic_id = 964 AND user_id = 4. "

The thread in which this happens changes over time and the SQL query also changes. The rest of the forum works ok so I’m cueless why this is happening…

May i know the mysql server name in this case?

Thank you tanmaya, this seems to have been repaired by your actions.