Ah, there is a related problem of running 2 or more SIP clients (or registrations) from behind the same NAT router.
When it was just one account had you previously used port forwarding to allow in 5060 (udp)?
(uPnP can also be doing this silently).
(Although in theory as it's to the same software and therefore same IP it should not really be a problem.)
Anyway have a look if your suppliers have alternative settings for clients behind NAT.
Something like "add a setting for a SIP proxy of nat.voipexample.com:5065" where they tend to specify a different port from the standard 5060.
In which case you can turn off any related port forwarding and each supplier will need to have their own SIP proxy added in the software (a per-account setting).
If the the software only supports a single global SIP proxy setting that is more likely to be your problem (then you can have multiple registered extensions but only with the same supplier).
If you have a router providing SIPPROXYD this can usually handle multiple registrations from behind NAT.
Ekiga is another desktop software client you can try (or cSipSimple on Android).
prompt $P - Invalid drive specification - Abort, Retry, Fail? $G
prlzx on n e w n e t: ADSL2+ / 21CN at 3.5Mbps / 800kbps
Edited by prlzx (Wed 22-Aug-12 09:14:50)