Problems installing GlScene :(

[T-Bear]

Hi, im having some problems installing glscene for lazarus, and hope someone can help me.
I downloaded GlScene, and opened the glScene_designtime package for lazarus, and tried to install it, and compiled the IDE. I got these errormessages:

C:\Data\Pascal\GLScene\Source\Base\VectorGeometry. pas(1257,11) Error: Function is already declared Public/Forward "SinCos(const Double,out Double,out Double);"
C:\Data\Pascal\GLScene\Source\Base\VectorGeometry. pas(1265,11) Error: Function is already declared Public/Forward "SinCos(const Double,const Double,out Double,out Double);"
C:\Data\Pascal\GLScene\Source\Base\VectorGeometry. pas(1369,10) Error: Function is already declared Public/Forward "MinFloat(const Double,const Double)ouble;"
C:\Data\Pascal\GLScene\Source\Base\VectorGeometry. pas(1372,10) Error: Function is already declared Public/Forward "MinFloat(const Double,const Double,const Double)ouble;"
C:\Data\Pascal\GLScene\Source\Base\VectorGeometry. pas(1381,10) Error: Function is already declared Public/Forward "MaxFloat(const Double,const Double)ouble;"
C:\Data\Pascal\GLScene\Source\Base\VectorGeometry. pas(1384,10) Error: Function is already declared Public/Forward "MaxFloat(const Double,const Double,const Double)ouble;"

Could someone please have a look at what im doing wrong / what is wrong? Thanks in advance!