The multi upload is working ok when uploading a couple of images, but if I upload about 20 3mb files quite some show "IO error" and don't get uploaded.

Any settings that could be changed to prevent this or maybe I should try different browser? Firefox 3.5 at the moment.

I don't have any real insights into what may or may not affect these uploads, but...

I've always found HTML uploads to be extremely finnicky; if you -can- FTP into your host, then I would highly recommend that over the HTML form. The images will still be recognized by zenphoto just fine and their details edited from the admin panel.

The multi upload script is js/flash based and has been adapted from here www.uploadify.com. Please also try to look on it's forum if this may be a limitation of itself.

Yea, found that out some hours ago, but my host seems to match all the requirements. I also tried increasing PHP memory limit to 128M and timeout to 60 sec, but nothing... The http upload is simply more convenient, as I don't have to make separate ftp accounts for uploaders.

It would be cool if you could upload zip with progress bar

The only way you get a progress bar is with the Flash based upload. It uploads zip files.

PHP memory limit is an advisory. Your server may not honor it. Also check the upload limits PHP setting.

Under the Flash based upload you mean the default and bundled uploadify? It only allows images to be uploaded, even if I type in filename.zip it uploads it and shows the progress bar, but the images won't get extracted to the album.

It does process zip files, so if your files are not showing up there must be some kind of error occurring. Perhaps the same memory restriction you mention above.

Not for me - it doesn't create a new album, if I try uploading zip to existing album it simply doesn't add the images to album.
No IO error this time, tried even a zip file with one 300kb image.

Offtopic: it would be nice if switching from one upload type to another it wouldn't reset the form parameters and album choice.

The processing of zip files is exactly the same for both upload paths. So, if it works in one case and not the other there must be corruption going on in the Flash upload.

Ok, thanks, I'll look into uploadify a bit and try to bug them on their own forum some. I'll post here if I find any solutions.