*Sob* - help please!

I've just starting using Mozilla Firefox as my default browser and get this
error message when trying to view a JSP in Netbeans:
(Browser fires up but doesn't autoload URL (goes to home page only))
------------------------------------------------------
... In the Options window, expand the IDE Configuration node.
Then expand the Server and External Tool Settings node followed by the Web
Browsers node.
Select the external browser type and modify the Browser Executable property
if necessary.
org.netbeans.modules.extbrowser.NbBrowserException:
DdeConnect errno >400A< when connecting to server IEXPLORE, topic
WWW_Activate.
at org.netbeans.modules.extbrowser.NbDdeBrowserImpl.reqDdeMessage(Native
Method) ...
-----------------------------------------------------------

Humm.. why the reference to IEXPLORE?

Tools->Options->...->External Browser(Windows)
-----------------------------------------
Browser Executable: F:\Progra~1\Mozill~1\firefox.exe
DDE Server: <default system browser>
-----------------------------------------
Chosen from drop-down list. I believe firefox IS my default browser.
(All worked OK before using Netscape or IE)

Thanks.

Julia