When i try to compile quanta 3.0 i get the error:

checking for dcopidl... /usr/bin/dcopidl
checking for dcopidl2cpp... /usr/bin/dcopidl2cpp
checking for mcopidl... not found
configure: error: The important program mcopidl was not found!
Please check whether you installed aRts correctly.

I have installed arts, and libarts 1, and kde-multimedia and kde-multimedia-dev packages, but it doesn't help.

I using debian sid & kde 3.0.4

As I can see in my system, mcopidl comes from arts. Are arts libraries in LD_LIBRARY_PATH or in a directory listed in /etc/ld.conf.so?

My /etc/ld.so.conf looks like:
/usr/X11R6/lib

/usr/lib/libc5-compat
/lib/libc5-compat
/usr/i486-linuxlibc1/lib

I´m not sure what you exactly mean.....

I also discovered that when i try to compile a theme for kde it comes with the same error.

But isn´t there a way to remove this from the configure stuff, i mean what would quanta use audiostuff for?

It looks it's not there... First find out where is your arts installed. Let's say it's in /usr/local/kde3. You need to type:
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/kde3/lib
And you should be able to pass this step in configure. Don't forget to add "/usr/local/kde3/lib" to /etc/ld.so.conf and run ldconfig. Then the change will be permanent.

Hihi, I discovered the problem: i missed to install the lib-arts1-dev package....

Ups, but now i got this when it tries to compile:
copytos.cpp:47: invalid use of undefined type `class KURLRequester'
copytos.h:17: forward declaration of `class KURLRequester'
copytos.cpp:49: no matching function for call to `QGridLayout::addMultiCellWidget (KURLRequester *&, int, int, int, int)'
/usr/include/qt/qlayout.h:325: candidates are: void QGridLayout::addMultiCellWidget(QWidget *, int, int, int, int, int = 0)
make[3]: *** [copytos.o] Error 1
make[3]: Leaving directory `/home/alien/install/quanta-3.0/quanta/dialogs'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/home/alien/install/quanta-3.0/quanta'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/alien/install/quanta-3.0'
make: *** [all] Error 2

HAve you installed the qt-dev packages?

Yep, both libqt3-dev & libqt3-mt-dev, and i can see it uses the mt in the ./config stage:

configure:20749: checking for Qt
configure: 20816: /usr/lib/qt3/include/qstyle.h
configure: 20816: /usr/lib/qt3/qstyle.h
configure: 20816: /usr/lib/qt/include/qstyle.h
configure: 20816: /usr/lib/qt/qstyle.h
configure: 20816: /usr/local/qt/include/qstyle.h
configure: 20816: /usr/include/qt/qstyle.h
taking that

configure:20988: result: libraries /usr/lib, headers /usr/include/qt using -mt

Try doing a "make distclean" on the quanta source.

I tried to delete the install dir, and unpack the tar file again, this did the trick and it´s now installed, don´t know your distclean makes the same trick, otherwise thanks for help

"make distclean" will restore the source code to the condition it was in when you first unpacked the archive, not all packages support it though.