column doesnt exist?

hi,

I created this table:
CREATE TABLE public.stresslog(
"AbfrageId" int8 NOT NULL DEFAULT
nextval('public."stresslog_AbfrageId_seq"'::text),
"AbfrageTyp" varchar(50) NOT NULL,
"Abfrage" varchar(300),
"AnzZeilen" int8 DEFAULT 0,
"ZeitVerbrauch" int8 DEFAULT 0,
"AnzCon" int4 DEFAULT 0,
"AnzSchreib" int4 DEFAULT 0,
"AnzLesen" int4 DEFAULT 0,
"AnzTabDs" int8 DEFAULT 0,
"TabName" varchar(100),
"AnzAnweisungen" int4 DEFAULT 1,
"SystemMeldung" varchar(100) DEFAULT 'OK'::character varying,
"AusfuehrungsZeit" date,
CONSTRAINT stresslog_pkey PRIMARY KEY ("AbfrageId")
) WITHOUT OIDS;

I try to execute the following statement and get this err.msg:
select AbfrageTyp from stresslog
->ERROR: Column abfragetyp doesn't exist

the same err.msg occurs to all other field ... that mean query like
"select TabName,Anzcon from stresslog" doesn't work.

I try SELECT * FROM STRESSLOG, that works fine.
what's wrong? It is a (known) bug?

please help

best regards

ps: enviroments: pgSQL 7.4.3 on SunOS