Smack 2.2.1 File Transfer + Google Talk = no worky?

I’'m using Smack 2.2.1 file transfer and it works just file with Wildfire server. But when I try to initiate/send a file via two google talk accounts (one to send, other to receive) the receiver never has its FileTransferListener.fileTransferRequest(FileTransferRequest) method called.

I can also see that the sender receives a negotation result with XMPPError #503

Thanksinadvance for any info.

Scott