[mythtv-users] MythWeb mysteriously stops talking to the backend [problem now different]

[f-myth-users@media.mit.edu]

    > Date: Wed, 15 Feb 2006 21:27:31 -0500 (EST)
    > From: f-myth-users at media.mit.edu

    >	Allowed memory size of 8388608 bytes exhausted (tried to allocate 137 bytes)

Partially solved:  I'd read the README and added the appropriate
"AllowOverride All" directive, but apparently the actual directory
I'd added it to was subtly misspelled.  But because MythWeb -appeared-
to be working fine, I didn't notice---until apparently various pages
it was trying to serve grew too large...

Unfortunately -now- it's giving me this warning at the top of every
page (and the pages otherwise look okay), so I'm presumably missing
another directory somewhere or have its permissions wrong:

  Warning at /usr/share/mythtv/mythweb/includes/init.php, line 50:
  session_sart(): open(php_sessions/sess_[big hash], O_RDWR) failed: No such file or directory (2)

/var/cache/mythweb has both image_cache and php_sessions
world-writeable, and image_cache has stuff in it clearly
written by mythweb, so I -believe- that it should also be
looking in php_sessions in that dir and that it, too, should
be writeable, but maybe I'm misinterpreting what this error
message is complaining about.  Line 50 is indeed session-start().

[The image_cache dir hasn't been touched since 0316 this morning,
but I'm reluctant to display the "Recorded Programs" page because
that's led to backend crashes in the past and the backend is currently
in use.  I can do so a few hours hence and see if I get any new PNG's
added there; could the directory being used suddenly change now that
the AllowOverride is taking effect?]

The actual /var/cache/mythweb/php_sessions directory seems not to have
been touched in months and is empty, so presumably mythweb never tried
to use it before.  There's nothing in the error log about what directory 
it might be trying to use, which is unfortunate.

Restarting my browser changes the hash but not the behavior.

[I'm running Apache 2.0.54 under Ubuntu Breezy, FWIW.]