Move to dir on hosting server gives cache failure

I have developed a mod-solution that I am now moving from dev into test and production.
dev is in dev-directory on hosting server, and I am now moving into test and production directory on same server.

I have followed instructions on: http://rtfm.modx.com/display/revolution20/Moving+Your+Site+to+a+New+Server
(cleared core/cache before move)

There is something fundamental wrong, since I get the following errors (from error.log, not all rows):
[2011-09-12 07:18:22] (ERROR @ /connectors/lang.js.php) Error caching lexicon topic lexicon/en/core/system_events
[2011-09-12 07:18:23] (ERROR @ /connectors/system/errorlog.php) Could not cache system settings.
[2011-09-12 07:18:23] (ERROR @ /connectors/system/errorlog.php) Could not cache context settings for mgr.
[2011-09-12 07:18:23] (ERROR @ /connectors/system/errorlog.php) Error caching lexicon topic lexicon/en/core/default
[2011-09-12 07:18:23] (ERROR @ /connectors/system/errorlog.php) Error caching action map mgr/actions
[2011-09-12 07:18:23] (ERROR @ /connectors/resource/index.php) Could not cache system settings.
[2011-09-12 07:18:23] (ERROR @ /connectors/resource/index.php) Could not cache system settings.

core/cache dir has permissions 750 and directories and files is created under core/cache,
Dirs have permission 750 and fileshave permission 640 when created.

The thing is that the files are created under core/cache/xx/xxx.yyy, but they are zero in length.
It seems that the files are created but modx cannot fill them with content.

I am using the same server, same account, just another directory on the server.

Note that all manager pages seems to work, but on the web-side, no chunks and snippets works.

Is there another permission I need to set?

Regards
Sven

I have also run setup->upgrade again without success.
Version is 2.1.3

Try changing core/cache to 755 and the files in it to 644.

Changed dirs to 755 and files to 644, but still the same...
Doublechecked if path to new dir was hard-linked, but the path checks out.

Moved to a test domain on the same server, and that worked without any problems.
Retried on the production domain, with the same steps as for the test domain, and still the same problems with the cache part.

The only difference between test and production domain is:
#1 Different databases (same content, workspace table changed)
#2 Different paths (changed all config files accordingly)

The path for the test domain is:
define('MODX_CORE_PATH', '/www/webvol17/40/9cn1xungy6qci7w/test.DOMAINNAME.se/public_html/core/');

The path for the production domain is:
define('MODX_CORE_PATH', '/www/webvol17/40/9cn1xungy6qci7w/DOMAINNAME.se/public_html/core/');

Is the problem with cache related to that I use 'DOMAINNAME.se' instead of 'www.DOMAINNAME.se'?

It is odd that MODx can create the files, but not fill them with content.
Any debug that I can turn on?

/Sven

Check who the unix owner and group is of your files on the new server. Sometimes permissions can be ok, but the web user that php runs under can be different to the one that your ftp connection uses. I have had this issue with a web site recently and it has driven me ka-razy.
I could install packages via the package manager, but not modify any files created via ftp
I could upload files through ftp, but not modify them using the filesystem manager in modx
If this is also your problem, I sympathise!

It is the same user and web-server for test, dev and prod... = no difference.
I even use same ftp account when uploading.

Can I turn on some more debugging? (or add in a modx-php- file?)

How is PHP being run? (phpsuexec or dso for example)?

According the hosting-partner, they run mod_php in apache (do not know if that is the right answer)

SOLVED
I talked to my hosting partner, and it seemed that production was run on another apache instance than dev and test.
After move of production to same apache server-environment as test and dev, all worked.
Thus, no setup problem with MODx, instead a tricky problem on their server.

Thanks all for all assistance!