Many thanks to go out to WordPress user rbredow for the assistance in isolating an interaction problem affecting some users of the plugin. Sites that have a PHP hardening plugin called Suhosin configured might experience a problem in attempting to upload files. After Picasa displays the upload dialog and you press the upload button, The Suhosin plugin might strip out the uploaded files from the request stream. This results in seeing a result page that Picasa failed to upload any files.
If Suhosin is configured, you might see an error like the following in the server error log:
ALERT - configured request variable name length limit exceeded - dropped variable 'http://localhost:51134/b921a58ec2806ab82f5399515fba226e/image/b0f008e85a4fa153_jpg?size=1024'
The fix is pretty simple. Check the Suhosin setting values for suhosin.post.max_name_length and suhosin.request.max_varname_length. A setting of at least 100 is recommended to allow the long variable names that are required by the Picasa engine. You might need to increase it further depending on the length of the dropped variable name observed in the error log.
One word of caution, in the last few months Google has deprecated the Picasa application APIs used by this plugin and has offered no replacement. At this point what it means is that the code in Picasa allowing buttons to be configured is unsupported and it might fail or be removed from a future release of Picasa.
The 0.5 release documents this interaction and also fixes some error reporting when uploads fail due to file system protection problems. Plus I’ve added i18n support so if someone wants to submit a translation, I’m happy to include it.
Thanks for using this plugin!