Problem installing a gimp plugin

[diego <ddc_prueba@yahoo.es>]

Hello.

I'm trying to install a gimp plugin, but the configure script
complaints:

checking for GIMP - version >= 1.2.0... no
*** The gimptool script installed by GIMP could not be found
*** If GIMP was installed in PREFIX, make sure PREFIX/bin is in
*** your path, or set the GIMPTOOL environment variable to the
*** full path to gimptool.

I have checked I have gimptool installed and in the path. I have also
tried to use:
./configure --prefix=/usr/bin
but with no luck.

Can any one give a hint? Thanx in advance.