Win2000, OO 1.0, Writer, StarBasic

I load and process writer-template with Star-Basic like this:

Dim mArgs()
oDocument = oDesktop.loadComponentFromURL
("file:///"+sPath+sFileName+“.stw“, "_blank", 0, mArgs)

oDocument.lockControllers()
oReplace = oDocument.createReplaceDescriptor
... ' Doing some replaces
oDocument.storeAsURL(sUrl, mFileProperties())
oDocument.unlockControllers()

The saving works here without problems. The document is not closed, because 
sometimes the user want to chang something manually and then saves the document 
manually with File->Save.

And HERE you get a "generall I/O-error while saving [sUrl]". The filename 
is just a 6-digit-number (like "000123.sxw")

I tried to do a manual File->Save as... (for example "000123_2.sxw"), but 
then OO gives the same error and says it could not save "000123.swx" (!) 
(but I wrote "000123_2.sxw" in the file-dialog-box...).

This is all very strange and it happens only when opening the template 
with loadComponentFromURL. It could not be an error of Win2000, because 
when opening the same document manually with File->Open, it all works fine. I 
used the same script in StarOffice 6.0 Beta and it worked, too.