Long story short:

We wanted to start using CAPTCHA. So, I went to turn it on in the CP. No ImageMagick available. No big deal. That's done and the binaries are now listed in the gallery settings. IM is now available. (Version: ImageMagick 6.2.8 04/17/08) It's weird that GD2 isn't available as an option for CAPTCHA as we've been using that for our gallery settings for a while and it's been working fine, but that's another issue (I think...)

So, I turn on CAPTCHA. I get a bad image (image not available, not pr0n. ) that comes up on the new user reg page.

So, I dig around ubbcentral and find this thread which describes my problem. When I run the basic CAPTCHA test (ubbthreads.php?ubb=captcha&type=im&test=1) I get "exec() is not available." So, I look at the php.ini file (the one listed in "admin/phpinfo.php.")

open_basedir= is commented out and safe_mode = Off.

/usr/bin/convert and /usr/bin/mogrify are each set to 755. (And I'm using the full binary path in the CP - as opposed to just the directory.)

images/captcha/* is set to at least read everything. cache/ is set to 777.

I tried restarting Apache/httpd as well.

What else is needed to run external scripts, or what am I missing?

(extra info: php 5.2.8. UBB 7.4.1. httpd 2.2.11)

edit: OK, I guess it's not weird that GD isn't available as an option. Freetype wasn't compiled in to GD according to php.info.

Sheesh... OK, I wish I had an answer, but this has gotta be something outside of ubb on the OS (CentOS). I just did a complete refresh of my test system (running Solaris w/ IM 6.3.4) and the test system's captcha worked fine. I'm assuming the differences in version of ImageMagick have nothing to do with it... right?

I did notice that I have a LOT more .ini files being scanned by php. My production box does not have any additional directories to be scanned.

Are the .ini files the place to start looking?

Definitely doesn't seem to be an imagemagick issue. Normally exec() would be disabled if you're running in safe mode, which it looks like you aren't. I'd check the "Disabled Functions" section of your phpinfo page and see if there is anything listed there.

I'll see if I can dig up any more suggestions.