[news.eclipse.platform] Prevented recursive attempt to activate part

[chrishe@xxxxxxxxxxxx (Chris)]

I have 2 views (using TreeViewer) that use
getSite().getPage().addPostSelectionListener(this) to chnage their input 
according the current selection. Their selectionChanged(..) method ignores 
any selections which aren't IFiles, so I shouldn't get my own selection 
changes.

When you click on one of the elements in the tree, the properties view is 
updated.

This works fine unless you start editing one of the values in the prop. 
view then go back to the tree. This causes the following entry to be 
placed in the errorlog:
WARNING: prevented recursive attempt to activate part 
org.eclipse.ui.views.PropertySheet while still in the middle of activating 
myView.

Found this: 
http://dev.eclipse.org/newslists/news.eclipse.platform/msg40562.html
but not sure what it means.
Anyone got any ideas?
Thanks in advance
Chris

PS the error in the log has a different icon (cross in front of paper) to 
normal (just a cross) and causes the log to take focus. Might like to use 
it in my plugin. What is it?