treeview_populatenode -> Input string was not in a correct format.

[Sandra]

Aspx-page with treeview:
When expand depth=1 and populatenodesfromclient=true the callback function
treeview_populatenode causes an error when using non english chars (ä ö ...),
which are sent in the argument-strings. How can I correct this?
For the moment I have changed to populatenodesfromclient=false and do
therefore not get this error, but I would like to be able to use
populatenodesfromclient=true.