12 mins my a***. (well for me anyway!) took about 45 mins but i finally got it.
Got a useful hint if noone has thought of it yet.
if you take rows eight and nine the total must be 90. which means r7,c1 and r7,c9 must add up to 6. given i had other numbers i was able to pinpoint which two numbers they should be. Similarly this works for rows one and two.
i hope i am not being too obvious but i thought it might help some of us who are still getting to grips with this great new version.