I would suggest the time of year may be part of the issue.

The 2004 tsunami (Dec 26) and the 2010 Haiti earthquake (Jan 12) happened in winter months, when I sit and watch TV a LOT. The scenes they showed where heart wrenching, and yes, I gave.

This time of year, I am lucky to watch 3 hours of TV per week. While I am aware of the floods in Pakistan, I am not seeing the images "in my face" every minute. So the impact, the "oh my gosh those poor people," and the feeling that something like that could happen to me, a random thing like that, well, that message is just not hitting me the same way.