I have a Jabber account on pädda@hot-chilli.eu. Notice the ä (U+00E4). This is allowed by
http://xmpp.org/extensions/xep-0029.html
"2.3 Node Identifier
Node identifiers are restricted to 256 bytes, They may contain any Unicode character higher than #x20 with the exception of the following: [...]"

With Kopete (and also Psi+), I cannot login on that account. It works fine with Pidgin. Kopete asks me for my password repeatedly, but does not recognize the correct one. It probably tries to some different account, like pdda@... or dda@... .

If I execute kopete from the command line, I get the error
> [15:46:41] Unknown signature value:  7 
> [15:46:41] Unknown signature value:  7 
> [15:46:41] Unknown signature value:  795                                                                           
> [15:46:41] Unknown signature value:  668                                                                           
> [15:46:41] unexpected version response
each time I type in my password. I get the same using psi+, so I'm assuming they use the same underlying library?

Reproducible: Always

Steps to Reproduce:
1. Have a Jabber ID with non-ASCII, UTF8 node identifier.
2. Try to login
3. Type in your password when prompted

Actual Results:  
Kopete maintains the password is wrong, even though it isn't

Expected Results:  
Login to the correct account

Version is 1.6.60 (opensuse Leap 42.1)