Interestning.

Two things I observe on your site now. The first time I view an image page, the image does not show up, but when I return to view it after going to the next page, it is there! Just refreshing makes it show up. (Unfortunately, if you refresh the image page, the captcha is regenerated.)

Then, viewing the full image gives an error saying the watermark image is not a valid PNG file. I presume it is the one that came with the zenphoto install, that was valid at least when it left the 'factory'. All told, looks like there is a problem with PNG files on your system. (The captcha is a png image.)

Hmmm...

Well, it doesn't do that for me...weird.

Its almost like the image is loading before it has been generated/cached, so a refresh makes it show up...Since the captcha is done on the fly, a refresh doesn't help the problem.

If there's any information I could fetch and relay that might lead in the right direction, let me know!

I just moved to a new host and captcha doesn't seem to be working.

http://www.jasetaro.com/gallery/

You should check your error logs. At least one host is treating the Captcha image as a 'threat'. On that site the user was locked out of logging onto his web management because of this. We have no idea why a simple PNG image was considered a threat.

Anyway, somehow the image is not getting generated. So we need to see why.

There's nothing in the error log but the raw access log show this:

406 Not Acceptable
/gallery/zp-core/c.php
http://www.jasetaro.com/gallery/random-photos/West_Point01.jpg.php

Oddly enough I just in the with my one hosts tech support guys and asked them take a look at the gallery... He said he could see the captcha image with both IE7 and Firefox 2.

The 406 error seems to be from some kind of filtering on the data. Not sure what this would be, since c.php just serves a PNG image it creates on the fly.

Yeah, I just talked to one of my hosts tier 1 tech weenies he says it's ModSecurity that doesn't like the something that the captcha script is doing. I'm not sure what it could be though.

Well, maybe the techs can figure out. If is is something we can change, then we will do so. But again, it is just a png image!

Thanks Mate, I'll open a support ticket with them and see what they can come up with.

Just to follow-up here's the response I received from Inmontion hostings tier 2 support:

"The way the captcha works isn't very secure, and our security module running on apache is blocking the Captcha image. This rule has been disabled from the server, and the Captcha is now correctly functioning."

The captcha is working now but I'd like to now exactly what it is they consider insecure.

I guess we would like to know that, too.

I've requested more information from them... I'll let you know as soon as I have an answer.

I really wonder what security is needed in generating a PNG!

Here's the specific error message from their logs:

/gallery/zp-core/c.php?i=%C58%CBb%F3 HTTP/1.1

"Access denied with code 406 (phase 2). Invalid Unicode encoding: invalid byte value in character. [id "950801"] [msg "UTF8 Encoding Abuse Attack Attempt"] [severity "WARNING"]"

HTH.

Interesting. At least we can figure out a way to deal with this.

There will be a fix for this in tonight's build.

Great, thanks.

We are indebeted to you for finding out what was being complained about.

Glad I could help... The thanks though should go to the folks at Inmotion hosting who were happy to provided the details.

Hi, I downloaded the lastest version of zen-photo but I'm getting the captcha error (www.brianbluebadge.com/gallery). Should I contact my server administrator in the meantime?