drop sequence in transaction

Hello

I have a litle problem with sequences.
I use drop sequence in transaction, is this possible?

If yes, then i have done:
1. begin
2. get some data
3. drop sequence s_acc
4. create sequence s_acc...
5. rollback

And after this the database responds like this:

test=# \d s_acc
Sequence "s_acc"
Attribute | Type
---------------+---------
sequence_name | name
last_value | integer
increment_by | integer
max_value | integer
min_value | integer
cache_value | integer
is_cycled | char
is_called | char

test=# select * from s_acc;
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
ERROR: cannot open relation s_acc
test=# select last_value from s_acc;
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
NOTICE: mdopen: couldn't open s_acc: No such file or directory
ERROR: cannot open relation s_acc
test=#

I realy don't know what means this?

Thank's for help...

Best regards
Ice Planet

e-mail: ice(at)adiemus(dot)sk
ICQ#: 67765483