filter values get lost

I'm using the latest versions of CCK, data and daterange.
I want to make a daterange filter on a cck date field, but when I hit the save button and edit the view again, whatever I entered for "from" and "to" in a custom daterange is lost and the fields are empty again.

It doesn't matter if I use strings like "today-1M" and "today+1M", or fixed date values, its all going to a big black hole ...

The value shown near the fields is always: a:2:{s:5:"date1";s:0:"";s:5:"date2";s:0:"";}
Checking the query in the views_views table, it ends with
LEFT JOIN {content_type_mytype} node_data_field_datum_0 ON node.vid = node_data_field_datum_0.vid WHERE (node.type IN ('rapid_match')) but nothing that tries to actually filter by date (field_datum_0 is the field I'm trying to use the daterange filter on).

If there's anything I can do to help fix this let me know.