DateTime compare or filter when use "Where" of EF4.1 Not work

Question

I am a new one on EF. I want to select all the records which is created today.

so I code:

content.XXRecords.where(r => r.ModifyDateTime >= DateTime.Today || r.CreatedDateTime >= DateTime.Today );

But the result is null and the number is 0. There is really one record created just few minutes ago.

so confused????

Then I debug it, when try to calculate the "content.XXRecords.where(r => r.ModifyDateTime >= DateTime.Today || r.CreatedDateTime >= DateTime.Today )"

It says "expression can not include lambda expressions" ???