2007 excel sumifs problem,

I am trying to us a sumif with multiple ranges and criteria but am having on
bug, with cell referenceing when using it with a greater or less than
criteria.

Example
sumifs(sum range, criteria range, <(G6))
where G6 equalls and input cell.
When I substitiute G6 with "<10" it works but when using a cell reference
instead of 10, nothing works.
Thanks.

David