  The wavefunction statistics at the Anderson transition in a 2d disordered
electron gas with spin-orbit coupling is studied numerically. In addition to
highly accurate exponents ($\alpha_0{=}2.172\pm 0.002, \tau_2{=}1.642\pm
0.004$), we report three qualitative results: (i) the anomalous dimensions are
invariant under $q\to (1-q)$ which is in agreement with a recent analytical
prediction and supports the universality hypothesis. (ii) The multifractal
spectrum is not parabolic and therefore differs from behavior suspected, e.g.,
for (integer) quantum Hall transitions in a fundamental way. (iii) The critical
fixed point satisfies conformal invariance.
