Can you tell the meaning of form_build_id
I am trying to solve problem "add to cart form breaks after using Exposed filter with Ajax"
As I investigated, only form_build_id value changes when we are trying to search product catalog for certain products with Exposed Filters.
If I take initial form_build_id value for product's add to cart form, search catalog with Exposed Filter, than substitute via Firebug new form_build_id value with initial, and the form works