Rega RB300 Arm Question?

Hey Guys, I just purchased a Rega P3 2000 w/rb300 arm. Last night I was trying to set-up a cartridge, I noticed that when I was trying to set the counter weight, the arm (while in floating position) kept swinging slowly over to the resting position. Both the tracking weight and anti were set to zero while this was happening. Is this normal? Keep in mind that the table is completely 100% leveled.

Thanks in advance,
Yea, man it's normal. Often, '0' on the anti-skate is not really 0 because the spring is still attached and provides some force. Usually, the reading you adjust on the anti-skate should be the same for high complient carts, and about half for low complient ones, and that arm should be fairly accurate despite some deflection at 0.
True enough, but even with a dynamic balance arm it is very important to level the turntable.