My suggestion would be to make it much more obvious when a draw is offered. I've played several games where a draw offer went unnoticed. Could you have it show up as a popup box or something. Or big, bold, flashing letters?
But, I've agreed before, and nothing happened.
I've usually resorted to putting a comment in the chat box to make sure my opponent sees that I've offered a draw.
I was once offered a draw (in the 16 online games i've finished), and i found out about it after the game was finished (thankfully, i won :) when i was going through my mailbox some days later.
I'm still wondering how a draw offer looks like XD
So, i agree 100%
I've considered doing what Casual_Joe said if i was to offer one.