I think the OP is looking for info on why the drive in his 5045 is having a hard time recognizing “-” media compared to “+” media. All Liteon dvd recorders, with or without HDDs, all have the same problem, initially built with a bad burner. The dual writer recorders such as the 5045 (and 5005), the use of “-” media has been discouraged in favour of the “+” media which these models seem to prefer. The first sign of a failing drive in these models is its increasing failure to recognize “-” media, eventually it will go to not recognizing “+” media. This is inevitable with all Liteon recorders hence the sticky threads on replacement drives on this and other forums.
As for changing the burning speed in these recorders, the speed is inherent to the chip which only allows two speed, real time and 4x, that’s it, there’s no way to increase the speed, it’s just the way it is. This forum would have been well aware of the possibility of changing this feature by now. So my only suggestions for now are stick with + media and start looking at replacing your burner.