Interval and mx.TimeDelta

Hi,

I'm trying to use mx.TimeDelta with an postgres interval data type
(through SQLAlchemy)
My psycopg version is:
2.0.6 (dec mx dt ext pq3)

It all works fine until I get to dates greater than a day;
ProgrammingError: (ProgrammingError) invalid input syntax for type
interval: "1:00:00:00.00"
I assume this should be in the format: "24:00:00.00"

Any advice?

Thanks,

Eoghan