I have the same problem with elastix 1.5.2-2 (the 64bit version) on a Intel D945GCLF2 motherboard with onboard atom 1.6GHz CPU/512MB RAM
I try to activate the IM (i.e. OPENFIRE) module and after a while it says "network error - this document does not contain any contents" (something like connection timeout)
If i press reload it gives me the page to active the IM Service so if i press again "ACTIVATE" it shows me the same error

((
Why this is happening?
(Just to let you know that on another machine i.e. Tualantin@1.3GHz the OPENFIRE IM module from 32bit Elastix v1.5.2 is working fine.
Regards,
John