When you create a task (ex : to call back) from with in the opportunity, max create a task for that opportunity
But if that particular day you right click on that task (saying that you have to call back the opportunity), and choose call back (by right click or phone Icon), the call back log will be store into the contact not into the opportunity.
Not good to have a proper follow up. It shoud log the call into the opportunity note, not into the contact note.
if you have the same bug just cut paste that text and send a email to suggestions@maximizer.com
After a coupple of complain they will fix it, and we will be able to work better with maximizer and faster.