Rails - Apr 2006 - acts_as_list not CASCADE''ing in singular n-tier model structure

[using RAILs 1.1.2]

Has anyone else seen issues where multiple tiered "acts_as_list"  
models do not CASCADE delete correctly? For instance, I have 4  
models, the first 3 in the hierarchy have the appropriate "have_many"
declarations with "exclusively_dependent => true". The last the  
models have the appropriate "acts_as_list" with the correct scope and
"belong_to" declarations. If I did not have PostgreSQL setup to  
CASCADE the FK constraints, deleting a model object on the 2nd tier  
would not go down to the 4th.

Does "acts_as_list" not support multiple tiers?