[ESS] Object name completion slow

[Offenthaler Ivo]

Hello all,
name completion (TAB or C-c TAB) for R objects is _quite_ slow and the name
database (?) seems to be rebuilt during the same session (ess-5.2.0, GNU
Emacs 21.3.1, R 1.9.1, Win32) - any hints appreciated!
Ivo