COUNTIFS - Time Issue

[kjcdude]

See screenshot here (http://i.imgur.com/Ck6oBuZ.png)

I'm trying to calculate the amount of arrivals that occurred between 10am and 10:59pm.
To calculate this i'm using countifs(arrivaltimerange, >=10am, arrivaltimerange, <11am)

The issue I ran into is the times are taken from the Arrival Date Time column. I use MOD(Arrivaldatetimecolumn, 1) which outputs just the time into the Arrival Time column.
For some odd reason the countifs function will not count 10:00am's. But if I type in 10:00am into the exact same cell as the one outputting 10:00 am through MOD, it will then see the 10AM and add it to the count.

It's very very bizarre since it ONLY happens on the ">=time" times and is directly related to MOD.

Any help would be appreciated.

Thanks

-- Edit
Even MORE bizarre.
If I do the countifs search for 10:30am it will correctly produce the result of 3.