Bug with sequence

Hi,

I recently installed pg 7.2.3 on my linux box and discovered that
there are some problems with datatype serial and sequence.

1.) If you create a table with a datatype serial, the corrsponding
sequence will be created, but if you drop the table the sequence is
not dropped.

2.) If you create a sequence and grant it to public one cant use
currval() until one used setval() or nextval().
"ERROR: midnr.currval is not yet defined in this session"

3.) Sometimes one gets 'not enogh privileges' error when using
nexval()

Am I the first one who discovered that?

Thanks
Thomas