cubase 7 audio drop outs on recording

Hi everyone…new to cubase…running version 7.0 on iMac 2.9 osx 1.8.3 8 gigs of ram…quad core…using presonus firebox firewire port thru thunderbolt…I have no problems with it running logic pro 9…but when i use it with cubase I need to put all my controls on the box to max…then when recording a vocal…if there is a short silence after a word is said…seems like the volume goes down but will pick up on the next word…is this the norm for it?..or did i setup device wrong for it?..thank you…also I have register the product but every time I open it it says to register it?

Update to 7.0.5, then have another look.