GIFT compilation error

Hi GIFT team,

I am trying to install gift-0.1.14 using gcc version 4.0.1 (4.0.1-5mdk 
for Mandriva Linux release 2006.0). When compiling, I get the following 
output:

  g++ -DHAVE_CONFIG_H -I. -I. -I../.. -DHAS_BOOL -DLINK_DYNAMICALLY -I../.. 
-g -O2 -DEF_PROTECT_BELOW=1 -DEF_PROTECT_FREE -DEF_PROTECT_ALIGNMENT=8 
-DEF_FILL=42 -D__GIFT_WITH_PERL__ -DPERL_DISABLE_PMC -fno-strict-aliasing 
-pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 
-I/usr/include/gdbm -I/usr/lib/perl5/5.8.7/i386-linux/CORE -MT 
CAccessorFactoryContainer.lo -MD -MP -MF 
.deps/CAccessorFactoryContainer.Tpo -c CAccessorFactoryContainer.cc  -fPIC 
-DPIC -o .libs/CAccessorFactoryContainer.o
../../libGIFTAcPerl/include/CAcPerl.h:125: error: invalid covariant return 
type for 'virtual std::pair<bool, long int> CAcPerl::URLToID(const 
std::string&) const'
../../libMRML/include/CAccessor.h:90: error:   overriding 'virtual 
std::pair<bool, TID> CAccessor::URLToID(const std::string&) const'
make[3]: *** [CAccessorFactoryContainer.lo] Error 1
make[3]: Leaving directory `/home/dayang/GIFT/gift-0.1.14/libMRML/cc'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/home/dayang/GIFT/gift-0.1.14/libMRML'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/dayang/GIFT/gift-0.1.14'
make: *** [all] Error 2

It would be very great if someone could help me with this.

Regards,
Dayang