FormView"s ODS not passing correct insert params to BLL. How to debug this?

Hi,

This is not the first time I'm using a formview in asp.net. But this time
I'm stuck and don't know how to solve this problem.
I have a formview with ODS that calls a BLL method on Insert. All of this
has been generated automatically by the framework (i.e. create/configure
data source wizard). I looked at the generated code and everything seems to
be normal. I.e. the have correct names and types and are
bound to correct fields in the form. Still, when I execute the Insert, the
correct BLL's method is called but all parameters passed to the method are
either null or uninitialized (e.g. DateTime displays year 1001, etc.) - I
used debugger to verify this.

I've been trying to figure out what is going on for many hours but with no
success.
Could someone please let me know what could be causing it or how to debug
it?

Thanks,
Bogdan