6.2.1 .xsession-errors

[utu]

So here's one type, representing 3/4 of my .xsession-errors:

(firefox-bin:####): Gdk-WARNING **: XID collision, trouble ahead

The four digits #### are not always the same.

This occurs using iceweasel 3.5.6-1 with Shockwave Flash Plug-in 10.1r53.

Disabling this plug-in makes these errors stop. Re-enabling and going to
nytimes site, for example makes the errors begin again.

I'm unaware of what, if any performance is not correct.

Disabling compiz and/or java have no effect I'm aware of.

Constructive comments welcome here.
Also, would like to confirm version numbers are standard for Knoppix 6.2.1.