WordPress MU

I'm running into a weird "white screen of death" problem. After messing around, adding new content, making changes to the theme code, etc. every 15-30 minutes or so I get the white screen of death.

Now the curious thing is, as soon as I get it I can hit a proxy website and view the site just fine, but if I go back to my FF3 direct url and hit refresh, still the white screen of death. After a little while, I don't know, 10 minutes or so, I hit refresh and everything is back to normal. I should note this is only happening with my site running MU. Not having this issue with anyone else's stuff.

What the h-e double-L is going on?

There is no php error even though I have php errors set to display on screen, nothing in an error log. I thought maybe it was my FF3 but then after working on it for a while in IE the same crazy thing happened.

I feel like crying...can someone help me figure out what's going on?

It's either the server failing to output the page (maybe heavy load or poor server) or a PHP error you're unable to see.

Is is possible for a php error to not show up in the logs or on screen? (both are turned on in php.ini).

How do I diagnose if it's too much load on the server? It's a pretty new (couple of months) VPS ..

Thanks!

Yeah, MU defaults to suppressing errors, giving a WSOD. :)

Well that's very unhelpful. How does one go about figuring out what the heck is causing it?

Theres a lovely little setting in your wp-config file that looks like this
//define('WP_DEBUG',true);

Uncomment it.

@croakingtoad: A systematic approach to troubleshooting should also help track down the problem, and might avoid the need to make sense of log file errors.

Try to remember, or work out, what you changed while messing around. That's what's going on; you've told us it was OK before that point. You could check modified dates on theme files, for example, to confirm which ones you changed.

Once you've got that, you can start eliminating the variables - your changes - one by one.

For example, copy your modified files, or rename them out the way, and replace them with the originals. See if the problem goes away. If so, put the modified ones back one at a time until you reproduce the fault.

Hope this doesn't offend. It just sounds from your plaintive "What the...?" like you're needing to develop these skills.

And I'll note there's more than one error log. Yes, it's frustrating.

Do you have any caching plugins enabled? or Gzip compression enabled on your web server? Also, when you get the white screen (OD) what happens if you clear the cache in your browser and then refresh?

I would love to hear if you found a solution, and what it might be?

It would be one of your plugins