SUMIFS error with blank cells. Fix or workaround?

I'm starting a new monthly task where I'll break down how much is owed (column G) for my loan office's accounts according to date made (column AE) and how far past due they are (column I). I need to set the past due ranges to be >= 30, 31 to 60, 61 to 90, and over 90 days.

So, given the certain date at the end of the formula, I have this for >=30:
=SUMIFS(G1:G10, I1:I10, "<=30", AE1:AE10, ">=1-1-13")

this for 31 to 60
=SUMIFS(G1:G10, I1:I10, ">30",B2:B10, "<=60", AE1:AE10, ">=1-1-13")

this for 61 to 90
=SUMIFS(G1:G10, I1:I10, ">60",B2:B10, "<=90", AE1:AE10, ">=1-1-13")

& this for over 90:
=SUMIFS(G1:G10, I1:I10, ">90", AE1:AE10, ">=1-1-13")

These work fine except my range is always going to vary and I'll have to do this for each of our loan classes every month. So, it's impractical and prone to error for me to establish each individual range or fill each sheet with something like "blank" to avoid this error. I'd really like to just use this formula:
=SUMIFS(G:G, I:I, "<=30", AE:AE, ">=1-1-13")
...and have Excel ignore empty cells. Is this possible? Is there another workaround?

Thanks for any help!!

Really? That's odd. I get an error message if any range is greater than the number of cells in that column. So if I use:
=SUMIFS(G1:G11, I1:I10, ">90", AE1:AE10, ">=1-1-13")

but is blank after G10, then there's an error. I've tried different combinations, but so long as the range extends past where I have values, there's an error. I'm using Excel 2008 for Mac if that makes a difference.

Sorry, I should have been more clear. Any combination, including if the ranges are all equal, will create the error if blank cells are present. For example:
=SUMIFS(G1:G11, I1:I11, ">90", AE1:AE11, ">=1-1-13")
will still create an error if there's no data after row 10. But, If I copy anything into row 11, like "blank", then the error disappears. Had to do a lot of trouble shooting to find this and when I noticed the problem, it did strike me as a crazy way to behave. IS this a glitch of some sort in my version of Excel?

Looks like it is a software glitch. Opened the file on a PC with Excel 2007 andthe formula worked fine with blank cells. How odd.