BUILT_SOURCES doesn't seem to work

[Bobby Dill]

I have written a Makefile.am and processed it with automake 1.10. Here's how
the file looks.
METASOURCES = AUTO

bin_PROGRAMS = pkgmaker

# This rule lets GNU make create any moc_*.cpp from the equivalent *.h
%.h: %.ui
    $(UIC) -o $@ $<
%.cpp: %.ui
    $(UIC) -o $@ -impl $*.h $<
# You have one .h file, it's called myapp.h. Therefore, here I list
# its mocced name, moc_myapp.cpp.
moc_%.cpp: %.h
    moc $< -o $@

pkgmaker_UI =
    sigcreatedlg.h
    sigcreatedlg.cpp

sigcreatedlg.h: sigcreatedlg.ui
sigcreatedlg.cpp: sigcreatedlg.ui sigcreatedlg.h

pkgmaker_SOURCES = pkgmaker.cpp $(pkgmaker_UI)
BUILT_SOURCES = $(pkgmaker_UI)

# set the include path found by configure
INCLUDES= $(all_includes)

# the library search path.
pkgmaker_LDFLAGS = $(all_libraries)
pkgmaker_LDADD =  ../dirlist/libdirlist.la
CLEANFILES = $(BUILT_SOURCES)

I get several warning when I run automake.
pkgmaker/Makefile.am:6: `%'-style pattern rules are a GNU make extension
pkgmaker/Makefile.am:8: `%'-style pattern rules are a GNU make extension
pkgmaker/Makefile.am:12: `%'-style pattern rules are a GNU make extension
How do I modernize these rules?
When I try to compile my app, I get a message stating that sigcreatedlg.h
does not exist, so the files in BUILT_SOURCES are not generated before the
rest of my app is compiled. What's the right way to do this?