Hi rullolex
 ... At the reboot mtpaint is not on the pc, I have to do the tcz extension? ... 
All files and links to files in  /bin, /dev, /etc, /lib, /sbin, /tmp, /usr, /var  are in RAM and get recreated every time you boot.
The contents for those directories come from the  initrd (core.gz)  and  .tcz  extensions. So if you want it to persist, you
need to create an extension.
If you look over here:
http://tinycorelinux.net/6.x/x86/tcz/src/mtpaint/The  compile_mtpaint  file contains build notes.
If you want to apply the  mtPaint_gmodule.patch  file you will probably have to do it manually since the  configure  file
has changed since the patch was created. The affected line numbers are  692  and  693.
Add  squashfs-tools  to the  tce-load  command.
Change  giflib-dev  to  giflib7-dev  in the  tce-load  command.
After the  cd mtPaint  command do this:
export DESTDIR="$PWD/package"After the  make install  command, do this:
mksquashfs $DESTDIR mtpaint.tczCreate an  mtpaint.tcz.dep  file containing:
giflib7.tcz
freetype.tcz
lcms2.tcz
libpng.tcz
gtk1.tcz
libXext.tczPlace  mtpaint.tcz  and  mtpaint.tcz.dep  in your  tce/optional  directory.
Load  mtpaint.tcz  and see if it works.