Hmm, I have a feeling it has something to do with the way Juniper distributes it's labels.
From the juniper-nsp list, I found the following information:
Label distribution control mode: ordered (not sure)
Label retention mode: liberal
Label advertisement mode: downstream unsolicited
(http://www.mail-archive.com/juniper-nsp ... 05038.html
If you check out the MPLS presentation from Prague, you will notice that the list of unsupported LDP features has the following items:
- Downstream on demand
- Ordered label distribution protocol
It is quite possible that (at least) one of these two features are in use by the Juniper LDP implementation.
Although I lurk the juniper-nsp list, I am by no means a juniper expert. My JNCIA book did not mention a way to change the LDP parameters, and as I don't have access to the restricted part of the juniper website, I cannot help you any further.
Anyway, this is just my theory.
The road to hell is paved with good intentions.