Clicking the "Preview" button on the node edit form creates duplicate nodes

Stock Drupal would not create nodes after pressing the preview button. There may be a contrib or custom module interfering with the handling of the form. Do you have any custom modules that alter the node edit form? What contrib modules do you have installed?

I'm experiencing the same problem in v6.16. Just upgraded from v5.22 and while I've cleaned up a bunch of minor issues, this one has me stumped. It's very simple and reproducible - when a node is created and preview is not used, it posts as normal. If preview is used before posting, there are at least 2 nodes created ( nodename, nodename-0, nodename-1, etc.). I've told users to avoid the preview and I manually clean up dupes, but it would be nice to figure out what's going on here.

jpmckinney -

Sorry, I didn't notice at first that you requested the site information. Here's the info for our site -

Environment -

We run on a virtual server ("cloud server") at Rackspace Cloud. 512 Mb RAM server instance.
CentOS 5.3
Apache 2.2.3
MySQL 5.0.77
PHP 5.2.11
Drupal 6.17

No custom modules, the following contrib modules: BBCode, Links, Links Admin, SMTP Authentication Support, Advanced Help, Backup and Migrate, DB Maintenance, Hall of Fame, Masquerade, Nodeaccess, Pathauto, Persistent Login, Sitenotes, statcounter, Token, Token Actions, Token Custom, TokenStarter, Troll, Rules, Rules Admin UI, Capcha, Image Capcha, Javascript Tools, External Links, Views, Views UI, Vote Up/Down, Voting API, XML Sitemap, XML Sitemap Engines, XML Sitemap node WYSIWYG API using FCKeditor

I get these entries in my drupal logs when I create a blog entry and use preview -

Promoted blog entry X to front page (note, it doesn't actually get promoted)
blog: added X
blog: deleted X
blog: deleted X (these are me deleting the duplicate blogs)

I should also mention that this is only a problem when new content is created, editing existing content has no problems that I've seen.

I have these errors when I do a table check in phpMyAdmin -

table users - warning - found row where the auto_increment column has the value 0

table 'node' - the following indexes appear to be equal and one of them should be removed: PRIMARY, nid

table 'view_view' - the following indexes appear to be equal and one of them should be removed: name, name_2

Some history - we use custom tokens to promote blogs to the front page when they get >5 votes, this appears to be working properly.

This site has been on drupal since version 4.something, I took over when it was up to v4.7 I believe. We upgraded to v5 and recently to v6. I had to fix collation issues in MySQL that I believe were there since the original install. Other than the preview/double post issue, everything on the site appears to work properly and we get 300-800 unique visitors per day.

Any help would be greatly appreciated

Hmm, this suggests there may be a problem with the upgrade path from Drupal 5 to 6. Hopefully someone with more experience in that will come along to have a look at this issue.

Well, when I upgraded my test site from v6.14 to v6.16 I had all kinds of problems (the test database was a version of the working database taken ~2 years ago, so it's identical in structure to the existing database except much smaller). My guess was that some of the stuff we've been carrying in the db since v4 contributed, but that's only a guess.

I'm experiencing the same problem. I never actually used the 'preview button and discovered this recently. I'll keep you posted about my improvements because I'm going to try to find the module that causes it. I believe that could be the only reason.
Cheers.