This is a very odd problem. I am able to attach/upload certain files, but not others. I'm not 100% sure about the exact types, but Word documents and .PDF files seem to be OK and I've been unable to upload JPG and RTF files. When I try to upload a file in Firefox, the spinner beside the name of the file in the upload file list spins forever. When I try to upload a file in IE it gives up and gives a "file upload failed" message. Nothing appears in the logs.
Could this be something to do with line length in files (eg. RTF), or perhaps binary vs text files???
Its nothing to do with the size of the files - the .RTF file is only 5kb and I can upload a 46KB Word .DOC file.
Some info: roundcube 0.9.5 apache 2.2.27-r4 php 5.5.15
main.inc.php: $rcmail_config['debug_level'] = 8;
php.ini (additions to default): display_errors = Off log_errors = On error_reporting = E_ALL allow_url_fopen=1 allow_url_include=1 upload_max_filesize = 20M post_max_size = 20M max_execution_time = 60