Biztalk Server 2004 AND SQL adapter error

Hi, I am seenig the below error messages on the Biztalk Server Event viewer. I am not that aware the Biztalk functioning and would like to know when such errors occur:

The Biztalk server connects to SQL Server 2000 Instance mentioned below as

InstanceName.

13h30,45s => The "SQL" adapter is suspending an outbound message going to destination URL:"SQL://Servername/InstanceName/DatabaseName/". Details:"[DBNETLIB][ConnectionOpen (PreLoginHandshake()).]General network error. Check your network documentation. ".

13h30,45s => The Messaging Engine has suspended "1" message(s) from adapter "SQL" due to failures in message processing. Please refer to Health and Activity Tracking tool for more detailed information on this failure.

13h30,45s =>The adapter failed to transmit message going to send port "SQL://Servername/InstanceName/DatabaseName/". It will be retransmitted after the retry interval specified for this Send Port. Details:"Unspecified error".

Any help is highly appreciated!!!