[Zope] Scarry BTreeFolder eats my 'contents' tab

Just as soon as I restarted Zope after placing the BTreeFolder in the Products dir, wham! all my files were disappeared!! It took me quite a while to collect the pieces of my minds and pulled them together again when I discovered through FTP that my files were still inside Zope. Back in the HTTP manage console I also found that the 'Contents' tab was gone, and it was the same with most of the folders in my Zope site. After removing the BTreeFolder from the Products dir, the 'contents' tab was back again. Everything seemed normal except the /Control_Panel/Products/ still had an entry of BTreeFolder. Really weild!! I'm running Zope 2.2.0b3 on NT4. Any idea to tame this beast is appreciated. RGDS Dirksen