Instead of being lazy I turned a little proactive and added some debug statments on the in and out packets with tags around the data as such.echo "In Packet:\n<".$data.">\n";This resulted in the following output.
[2006-07-01 03:06:44]   [LOGIN] [STATUS]        Connecting
In Packet:
< 35199d1cdb4a38d35250fd19883a6773>
[2006-07-01 03:06:45]   [LOGIN] [STATUS]        Authenticateing
Debug key:
<35199d1cdb4a38d35250fd19883a6773>
<#Acount#>
<#Password#>
Out Packet:
<
#String removed cause it's got encrypted info about my account (^_^)#>
In Packet:
<0Authentication failed: Illegal alias or password>
[2006-07-01 03:06:47]   [LOGIN] [RESULT]        Error
[2006-07-01 03:06:47]   [LOGIN] [STATUS]        Logging in
AOChat: not expecting login.
So if it's to be believe it is rejecting my alias or password though I know both are fine.  I ran the same debuging AOChat in windows and the output is pretty much similar only with funky characters in place of whitespace.
[2006-07-01 03:13:59]   [LOGIN] [STATUS]        Connecting
In Packet:
<  dd59447eca221ac62c2bbebfc5a08233>
[2006-07-01 03:14:00]   [LOGIN] [STATUS]        Authenticateing
Debug key:
<dd59447eca221ac62c2bbebfc5a08233>
<#Account#>
<#Password#>
Out Packet:
< ??ô
#ConnectionString#>
In Packet:
< ?f÷Xx #BotName# ?   ? ?    >
[2006-07-01 03:14:00]   [LOGIN] [STATUS]        Logging in
Out Packet:
< ? ?f÷Xx>
In Packet:
<>
[2006-07-01 03:14:01]   [LOGIN] [RESULT]        OKI also have just tried the modified AOChat that Icidw posted and came up with the same error, that AOChat also works on the windows box.  The only other thing I can think of is the locales, my box is fully utf8 unicode based and php is also compiled with the unicode flag.

Damn, and i have hardware here planned to become a hardened webserver..

I guess we could use a complete rewrite of AOChat compliant to hardened php.

I'm going to add some debug statements to make it easier to distinguish which method is being used to generate the login hash. Check back later today.

The main problem right now is that the php methods are highly unreliable due to changes in PHP, and updates are badly needed to the hash generation code in the AOChat php library. However that requires good maths skills aswell as php knowledge, which puts it a bit out of my league

Hrm. I have no idea then

Yeahhh... I've fixed the problem

I got the tip, that on Ubuntu sometimes the libraries libgmp3c2 and libgmpxx3 are installed with unresolved dependencies. But these packages are needed for aokex to work correctly.

I've removed the packages and compiled them by myself (downloaded on http://www.swox.com/gmp/#DOWNLOAD). It's recommened to use the 'make check' command as described in the install instructions.
After installing the new library, I compiled again the aokex module against these library and now it works

Afterwards I saw, that it's possible to switch the compilation of aokex to openssl (I should learn to read the manuals more exactly). Perhaps this would also be a possible way to solve the problem.

A modified aochat.php never fixed the problem for me. You should use the aokex fix.

tried both openssl and GMP in Ubuntu no luck :§
box runs dual xenon cpu.

Hurtig, this is indicating that you are missing parts of the GMP library, possibly the actual library itself.
You could also try the OpenSSL method instead of GMP.