[Libreoffice] UPR local host problem

Hi,

I've made a UPR client from scratch with Embarcadero Delphi
my purpose is to talk to a LibreOffice server without any dependency

I've made a test program available there:
www.execute-info.com/RemoteOfficeDemo.zip

this Windows application call the specified office server to open and 
convert a document to PDF

you just need to put the office IP address and port number (default are 
127.0.0.1 and 8100) and press "Convert to PDF"
the current displayed text should be converted to RemoteOffice.PDF.

BUT, and that's why I post this mail, this program work perfectly on a 
remote office, but hang on a local host.

the very special thing is that when a first instance is hanged, a second 
one work just fine !

How is-it possible ?!

I debug mode, the socket doesn't receveive anything after the message :
 loadComponentFrom('private_stream', '_blank', ...)
and my program is still waiting a reply for ever :(

the first to tabs are using "XInitialize" to send the text, the 2 other 
tabs are using XInputStream to handle large files.

Regards
Paul TOTH