This is a known issue in 7.0r1 and it has been fixed in 7.0SPkA. There is a Hotfix available for version7.0r1 and the Hotfix file name is HF700R137835.zip. This issue could be found if you are using MsgBrdcst function directly to broadcast a message between servers or if you try to use along with MsgOpen() function. In the Msgopen function the call back function is not called since the MsgBrdcst doesnt broadcast the message and other server never receives the message. Once you apply the fix the issue will get resolved.