in answer to your question you can run two lines at the same time, whether using mgcamd or oscam but from my own experience, like has already been mentioned if one is acting really poor and glitching like crazy if its got a better response time then the softcam will choose that one, its really annoying and I didn't understand it properly at first so I was wondering why the poor line was always running and I even thought both lines were poor at one point, If both lines are fairly good though and are comparable to one another then you will regularly see them in the softcam manager or depending on what skin you have on your box you can see them switching by pressing info, myself I just run one line nowadays as its less hassle, just find a good provider and stick with them.