[TYPO3] Hook is not called in just ONE installation, why?

[Matthias Stuebner]

Hello all,

today I transferred an extension on a customers server and was surprised
that a hook isn't working!

- Both installations are 4.0.4 (direct copy)
- TYPO3 settings in install tool: compared, setting by setting => identical
- Real Server: Linux, local: WinXP

The hook is defined using:

$TYPO3_CONF_VARS['SC_OPTIONS']['tslib/class.tslib_fe.php']['contentPostProc-output'][]....

which does fine on my local maschine, but not remote. The line above is
entered in extensions ext_localconf.php, but I tried main localconf.php too
and I'm mostly sure that I always deleted all temp_cahcedxxxx files.

Does anyone have an idea what to look for. Can there be a php-setting that
prevents the hook from beeing executed?

How would you debug that? I.e. a debug call in the hook function doesn't
show up, so I'm mostly sure that the function isn't called at all. Anything
else is working finest.

Thanx in advanced (from rainy Munich)
-- 
br Matthias