Issue with setting up a formula with more than one condition

Hey, I am having some issues setting up a forumla for a user. I would use SumIF which I know how to use but unfortunately this forumla needs to check on two conditions. I would use SUMPRODUCT but I am not very confident with and and looking around on the internet I have only found some guides which confuse me further.

I have tried using the Conditional Sum Wizard however it seems to work but it doesn't actually update the values past the first cell with the values that the forumla is looking for.

In the spreadsheet I have seperate worksheets which all have information in them that needs to be summed up onto the first worksheet.
The conditions are that if GE Business = Commercial Finance
and Category of Work = 1 then the cumulative total value that is relative row wise to these cells should be summed up into the first cell of the Reporting template worksheet headed Redundancies.
Probably easier if I just show the forumla that the condition sum wizard gives me to be honest...
=SUM(IF('London 2011'!$J$3:$J$51=G1,IF('London 2011'!$A$3:$A$51=H1,'London 2011'!$M$3:$M$51,0),0))

Spreadsheet is here: https://docs.google.com/open?id=0B4h...c0MTg3OTJjOWNl
and attached to the thread.

Any help would be greatly appreciated!