The following piece of code ICEs 3.4 (20030729). This is a regression
on the 3.4 branch because 20030620 compiled the code just fine.
Compile with -O3.

----------------------- cut ---------------------------
template < class > struct ConstVector
{
	virtual ~ ConstVector () ;
} ;

template < class D > struct Vector : virtual ConstVector < D >
{
} ;

template < typename , typename > struct X ;

Vector < X < double , long > > DoubleVector ;
----------------------- cut ---------------------------

I'll no retest with a more recent version of 3.4.

   regards  Christian