2005/09/30 tough puzzle from sudoku.com.au

Initial position :

1) Easy eliminations :

b3=6%row, a5=6%block, c3=7%row, b1=3%block, c8=3%block, b8=4%block, i3=3%block, h4=3%block, a1=2%row, e1=1%row, d2=4%block, f2=2%block, i9=1%row, e7=9%cell, f7=3%cell, d5=3%block, g5=7%row, h2=7%block, g2=6%block, i2=9%block, f5=9%row, d3=9%block, f3=5%block, e3=8%block, c5=1%row, a2=1%block, c2=5%block, b2=8%block, i5=4%row, c9=2%cell, b4=2%row, d7=2%cell ,
lead to (for better reading, only remaining possibilities in still empty cells are written) :

2) 45 in Ch are in h17 so a9=5%row and a7=8%cell . We're now at :

3) Look at 7 in Bb8 : whether it's in a8, in which e9=7%row, or it's in b9, in which a4=7%col : e4=4%cell . From here it's straight to end.

(Details if needed : c6=4%block, c4=8%block, f6=8%block, e6=6%block, f8=6%block, h9=6%block, d8=1%block, e9=7%block, a8=7%block, b9=9%block, a4=9%block, b6=7%block, d4=7%block, d6=5%block, g4=5%block, h7=5%block, i1=5%block, g1=8%block, i8=8%block, g7=4%block, h1=4%block, h8=2%block, g8=9%block, h6=9%block, i6=2%block, g6=1%block, f4=1%block )