Are you talking about the smaller VS Equalizer (I tend to call it channel-EQ), or the more complex Master Equalizer? I'm asking because we had a similar problem with the latter in an early version, but this bug is supposed to be fixed since quite some time now.
Please tell us which build of the Vienna Suite you have installed (click on the name of the plugin to open the "About"-screen).
Apart from that I can just say that I was testing - and in fact creating many of the Presets - using either Nuendo 3 or Nuendo 4 on a WinXP-based machine. Obviously I didn't encounter this behaviour, but our developers will of course look into it ASAP.
Best,
/Dietz - Vienna Symphonic Library