problem with postgre

when i load up my pt ive been getting the following error
Unable to connect to PostgreSQL database:
PT3_2010_10_09_115047
Reason: Unable to login to database
(PT3_2010_10_09_115047). Reason: could not connect to
server: Permission denied (0x0000271D/10013) Is the server
running on host "???" and accepting TCP/IP connections on
port 5432?
help plz
Unable to connect to PostgreSQL database:
PT3_2010_10_09_115047
Reason: Unable to login to database
(PT3_2010_10_09_115047). Reason: could not connect to
server: Permission denied (0x0000271D/10013) Is the server
running on host "???" and accepting TCP/IP connections on
port 5432?
help plz