Emitting signal causes CRASH

[navi1084]

Hi,
I have Shape class which emits many signals to its parent widget. I have signal which emit from shape whenever user move the cursor on widget. Deletion of recent created shape is working fine. but when i move the cursor on widget and shape try to emit the signal for existing shape. Then i get the error in "if (signal >= connectionLists->count()) " of
void QMetaObject::activate(QObject *sender, int from_signal_index, int to_signal_index, void **argv)

The error Description is:
Unhandled exception at 0x671aacfc (QtCored4.dll) in Myapp.exe: 0xC0000005: Access violation reading location 0xa0000008.

Can anyone please help me out.

Thank You