If you accidentally de-activate a view (on of the 4 "homescreens") all configuration on it goes **bleep** up - and the view becomes blank when you re-activate it. It would call that for a bug.
Have a look at bugs.maemo.org and maybe you can submit it for attention of a developer.
That being said, I would imagine dropping the content of a view to be normal behaviour, when compared to other multiple desktop systems I've used in the past 15 years.. Traditionally, all the stuff on the desktop that is being deleted gets dumped on one of the remaining.. A bit cluttered, but you wouldn't loose anything..
Thing is on the N900, it hasn't lost any information, you just need to activate the items again
Think about this.... Maemo only allows you to to put unique instances (one, uno, 1) of shortcuts, widgets and contacts on any of the desktop pages. So if it did not flush the content from the de-activated page, the content on that page would no longer be available for you to add on another active desktop.
Which would cause people to say that it's a bug for the desktop to operate in that manner.... This is not a bug, but a failure of the documentation to explain how the desktop works.
Hope this helps
Well it would be nice with a warning - or a mini representation of the views where you enable/disable views. Kind of hard to see what is on each screen before you disable them.