Error when start OpenERP6.1 Server from prompt in ubuntu 10.04

I am using Openerp 6.0.3 and running smoothly on Ubuntu 10.04

Now i try OpenERP 6.1, but when i try to start Server below error displayed.
i have tried to solve this by installing all of the modules/packages listed in setup.py file in server,
but problem still now continue

===========Error when start============

./openerp-server --addons-path=../addons-6.1/,../web-6.1/addons/
2012-06-01 07:05:21,947 1809 INFO ? openerp: OpenERP version 6.1
2012-06-01 07:05:21,947 1809 INFO ? openerp: addons paths: /home/merlin/openERP6.1/addons-6.1,/home/merlin/openERP6.1/web-6.1/addons
2012-06-01 07:05:21,948 1809 INFO ? openerp: database hostname: localhost
2012-06-01 07:05:21,948 1809 INFO ? openerp: database port: 5432
2012-06-01 07:05:21,949 1809 INFO ? openerp: database user: merlin
2012-06-01 07:05:21,949 1809 INFO ? openerp.service.netrpc_server: starting NET-RPC service on 0.0.0.0:8070
2012-06-01 07:05:21,955 1809 INFO ? openerp.netsvc: Starting 1 services
2012-06-01 07:05:22,585 1809 CRITICAL ? openerp.modules.module: Couldn't load module web
2012-06-01 07:05:22,586 1809 CRITICAL ? openerp.modules.module: No module named wsgi
2012-06-01 07:05:22,586 1809 ERROR ? openerp: Failed to load server-wide module `web`.
The `web` module is provided by the addons found in the `openerp-web` project.
Maybe you forgot to add those addons in your addons_path configuration.
Traceback (most recent call last):
  File "./openerp-server", line 252, in <module>
    openerp.modules.module.load_openerp_module(m)
  File "/home/merlin/openERP6.1/server-6.1/openerp/modules/module.py", line 409, in load_openerp_module
    __import__('openerp.addons.' + module_name)
  File "/home/merlin/openERP6.1/server-6.1/openerp/modules/module.py", line 139, in load_module
    mod = imp.load_module('openerp.addons.' + module_part, f, path, descr)
  File "/home/merlin/openERP6.1/web-6.1/addons/web/__init__.py", line 3, in <module>
    from . import common
  File "/home/merlin/openERP6.1/web-6.1/addons/web/common/__init__.py", line 2, in <module>
    from . import http
  File "/home/merlin/openERP6.1/web-6.1/addons/web/common/http.py", line 26, in <module>
    import werkzeug.wsgi
ImportError: No module named wsgi
2012-06-01 07:05:22,590 1809 INFO ? openerp: OpenERP server is running, waiting for connections...
2012-06-01 07:05:22,621 1809 INFO ? openerp.wsgi.core: HTTP service (werkzeug) running on 0.0.0.0:8069

i can't understand the error about 'wsgi' module in above.

Thank you in advance.