[Serusers] :: The best Softphone ?

[abdoul]

Hello,

I'm using Xlite v1 and 2 but always having so strange behaviors with SER 
O.8.12:
(direct connection , public ip - to - public ip)
- with xlite v1 and/or v2 , when i try to make calls : xlite always send 
404 not found to the caller (numbering plan: xxx-xxx-xxxx)
- no problem to reach someone with Xlite when I type the login
- when i make a call with Mitel 5055 or W. Messenger 5 no problem (vice et 
versa, both direction)

I tried with siemens softphone, good behavior but not user friendly

Now the question is , is there any other *free* good softphone for windows 
or is there anybody facing the same problem and know how to resolve it?

regards
abdoul