$13.250 \pm 0.052$ & $0.010 \pm 0.002$ & $0.35 \pm 0.34$ & $0.146 \pm 0.014$\
2006.14 & 22 Feb 2006 & 15 & 66 & (c) & $13.238 \pm 0.053$ & $-0.002 \pm 0.003$ & $0.18 \pm 0.35$ & $-0.024 \pm 0.020$\
2006.38 & 20 May 2006 & 15 & 100 & & $13.233 \pm 0.055$ & $-0.007 \pm 0.006$ & $0.39 \pm 0.36$ & $0.184 \pm 0.028$\
2006.54 & 16 Jul 2006 & 15 & 73 & & $13.236 \pm 0.055$ & $-0.004 \pm 0.005$ & $0.43 \pm 0.36$ & $0.221 \pm 0.031$\
2007.13 & 19 Feb 2007 & 15 & 110 & (d) & $13.240 \pm 0.059$ & $0.000 \pm 0.010$ & $0.34 \pm 0.38$ & $0.128 \pm 0.044$\

Remarks: For each VLT/NACO observation, we list the pixel scale determined with its absolute error and the change in pixel scale since the first new observation (2005.4), always with the same astrometric standard star HIP 73357; same for detector orientation in the last two columns.\
(a) Each image consists of 200 exposures with 0.347 sec each, for both GQ Lup and the astrometric calibration HIP 73357. (b) Results from 2004.48 as in N05, no relative errors available, because another 