Camera shake when shooting with 70-200 f/2.8 on a tripod.

[aistomin]

Hi,
When shooting with heavier lens (Sigma 70-200 f/2.8, 1.3kg on Canon 5D mkII) I noticed some camera shaking right after the shot. It looks like the mirror closing causes this.I was using Gitzo GT1541 tripod and Joby Ballhead X, which should be ok for body (0.811kg) with the lens (1.370kg), which totals to 2.181kg. The lens was mounted using tripod collar.
I just got the tripod and the head, and the lens was not mine, so I'm not very familiar with this configuration.
I used Slik Able 300 DX until now with same body and Canon 24-70 f/2.8 and I don't remember noticing these shakes.

So, is this tripod/head combination good enough for 5D mkII with tele lens like the above ? Any known workarounds ?

Thanks,Anatoly.