Lift as heavy as you can for 6-8 reps on your working set. Check out Marcus's thread in Lounge -
http://forums.steroid.com/anabolic-l...ary%2A%2A.html
It's all about going your hardest on your working set, cuttin or not. Doesn't matter. If you're a lot weaker, maybe you are cutting your calories too much. Maybe just add more light cardio instead.
The only reasonthe myth of lighter weights and higher reps for cutting ever started was because you can't lift the same heavy weight with less fuel. But, you still lift as heavy as you can.