[HCoop-Help] 500 errors with drupal site

[Andrew T]

I am trying to get a drupal 6.12 site running against postgresql. The
site seems to be functional, but I get a lot of random 500 errors with
the following error php messages in the error logs:

   [Tue Jul 07 12:39:44 2009] [error] [client 207.107.190.68]
SoftException in Application.cpp:483: Could not execute script
"/afs/hcoop.net/user/a/an/andrew/oss_html/index.php", referer:
http://ottawasuzukistrings.ca/admin
   [Tue Jul 07 12:39:44 2009] [error] [client 207.107.190.68] Caused
by SystemException in API_Linux.cpp:453: chdir() failed: Permission
denied, referer: http://ottawasuzukistrings.ca/admin
   [Tue Jul 07 12:39:44 2009] [error] [client 207.107.190.68]
Premature end of script headers: index.php, referer:
http://ottawasuzukistrings.ca/admin

When I refresh the page once or twice in the browser, eventually the
page displays correctly (is something timing out?). Has anyone else
had this problem with a drupal or php site? Is seems like apache
*sometimes* can't chdir to ~andrew/oss_html, which is the document
root for this domain.  I don't really know where to look next.

Suggestions are welcome...

Andrew

My permissions:

andrew at mire:~$ fs la oss_html/
Access list for oss_html/ is
Normal rights:
  system:administrators rlidwka
  andrew rlidwka
  andrew.daemon rlidwka

My domain configuration:

dom "ottawasuzukistrings.ca" with
  web "www" where
    DocumentRoot = (home "oss_html");
  with
    serverAliasDefault;
    directory (home "oss_html") with

          (* Don't show directory listings for URLs which map to a directory. *)
          unset_options [indexes];
          (* Follow symbolic links in this directory. *)
          set_options [followSymLinks];
          (* Make Drupal handle any 404 errors. *)
          errorDocument "404" "/index.php";

          (* Set the default handler. *)
          directoryIndex ["index.php"];

         rewriteBase "/";
          rewriteCond "%{REQUEST_FILENAME}" "!-f" [];
          rewriteCond "%{REQUEST_FILENAME}" "!-d" [];
          rewriteRule "^(.*)$" "index.php?q=$1" [last,qsappend];

          rewriteCond "%{HTTP_HOST}" "^www\.ottawasuzukistrings\.ca$"
[cond_nocase];
          rewriteRule "^(.*)$" "http://ottawasuzukistrings.ca/$1"
[last, redirectWith permanent];
        end;
  end;