Error changing panel properties when it contains a TreeView or Menu

[gilak]

In VS2005, when changing the propery of any panels containing a
TreeView or Menu I get the following error:

Error parsing control: Object reference not set to an instance of an
objec ..

Does anyone aware of a workaround to this problem?

[ca8msm]

Can you supply more information, such as the aspx code for the Panels
as well as the code which is producing the error?

[gilak]

On 20 Aug, 14:05, "[e-mail]"
<[e-mail]:

Can you supply more information, such as the aspx code for the Panels
as well as the code which is producing the error?

No code is involved. I just drop a panel onto a webfrom and then a
treeview or menu control within the panel. If i change any property of
the panel such as background colour I get thhe following error:

Error parsing control: Object reference not set to an instance of an
objec ..

I think this problem surfaced after I applied sp1. Any idea how can I
uninstall sp1. Ii does not appear in the list of installled software
in Add Remove Program.