Connector binds to the wrong side of the task, when I'm using the connector context short cut from a collapsed pool to the task.
The problem is very rare but can happen if you have a collapsed pool and task that are to close to each other. Then, even if you move one the of the elements, the message flow will still stick to the old edge.
To avoid this problem you should leave more distance between the two elements. Try also to place the message or sequence flows in the middle of the elements, so the connectors can be automatically attached correctly.
KBA , BPI-SIG-PM-MOD-EDT , Graphical Editor for SAP Signavio Process Manager , How To