snapshot stop causes Connection errors

Hi!
We do have 2 DSS. iSCSi-Targets DSS1 is replicated to DSS2.
At DSS2 side we are backing up the volume data by creating snapshots an connecting them to windows machines
Whenever we stop a snapshot it will cause a lot (aprox. 5) of Error messages at the event log of all
associated windows machines.

such as:

Source: iScsiPrt
Message: Connection to the target was lost. The initiator will attempt to retry the connection.

Source: iScsiPrt
Message: The initiator could not send an iSCSI PDU. Error status is given in the dump data.

Source: iScsiPrt
Message: Target failed to respond in time for a login request.

Source: iScsiPrt
Message: Initiator failed to connect to the target. Target IP address and TCP Port number are given in dump data.

Source: iScsiPrt
Message: Initiator failed to connect to the target. Target IP address and TCP Port number are given in dump data.

Source: MSiSCSI
Message: iSCSI discovery via SendTargets failed 0xefff0003 to target portal *10.111.1.1 0003260 Root\SCSIADAPTER\0000_0 .

The touble ends after aprox. 10 Seconds

How can we solve this?

Is there any registry key to encrease the timeout value of the MS iSCSi-Initator
If tested MaxRequestHoldTime, but it was not successful