Problem compiling PostGIS 1.1.4

PostgreSQL 8.1 on ubuntu-linux 6.06 (kernel 2.6.15-27-686):

Compiled proj-4.4.9 and geos-2.2.3 without problems.

Output from postgis-./configure-Command:

SUMMARY
-------------------------------------------------------

HOST_OS: linux-gnu

PGSQL: /usr/bin/pg_config
GEOS: /usr/local/bin/geos-config (with C-API)
(ldflags: -L/usr/local/lib)
PROJ: prefix=/usr/local libdir=/usr/local/lib
ICONV: 1

PORTNAME: linux
PREFIX: /usr
EPREFIX: ${prefix}
DOC: /usr/share/doc/postgresql-doc-8.1/contrib
DATA: /usr/share/postgresql/8.1/contrib
MAN: /usr/share/postgresql/8.1/man
BIN: /usr/lib/postgresql/8.1/bin
EXT: /usr/lib/postgresql/8.1/lib (\$$libdir)
-------------------------------------------------------

make check with problems:
"...ERROR: function postgis_lib_version() does not exist
HINT: No function matches the given name and argument types. You may
need to add explicit type casts...."

Running lwpostgis.sql on my database results in multiple errors:
"BEGIN
psql:lwpostgis.sql:39: NOTICE: type "histogram2d" is not yet defined
DETAIL: Creating a shell type definition.
psql:lwpostgis.sql:39: ERROR: could not load library
"/usr/lib/postgresql/8.1/lib/liblwgeom.so.1.1": libgeos_c.so.1: cannot
open shared object file: No such file or directory
..."

What went wrong?