every time i try to run a ./configure to compile things such as xmms-arts plugin or the xmms-jack plugin -- it gives me the following message:

** The xmms-config script installed by XMMS could not be found.
*** If XMMS was installed in PREFIX, make sure PREFIX/bin is in
*** your path, or set the XMMS_CONFIG environment variable to the
*** full path to xmms-config.

configure: error: *** XMMS >= 1.0.0 not installed - please install first ***

which is complete bull cuz i run xmms.1.2.10 all the time!

can someone help me and tell me what am i supposed to do to let it know that its installed?

Try setting the XMMS_CONFIG environment variable in your .bash_profile:
XMMS_CONFIG=/full/path/to/xmms
export XMMS_CONFIG

now try to "source .bash_profile", and then try running ./confiure again

I hope this helps
--Ian

nope that hasn't seemed to have done anything
-- i get the following error message:

bash: XMMS_CONFIG: command not found

export XMMS_CONFIG=/full/path/to/xmms-config
should do the trick, before running the ./configure script. Also check ./configure --help for relevant options.

You need the developement files for XMMS installed when compiling it is not enough to have the user package installed. In Debian the package is called xmms-dev.