RoundCube in EPESI has its own .htaccess file in modules/CRM/RoundCube/RC/.htaccess
Is this file that you've changed?
From RoundCube INSTALL file:
[quote:2mxnhkf1]You can also modify the default .htaccess file. This is necessary to
increase the allowed size of file attachments, for example:
php_value upload_max_filesize 2M
[/quote:2mxnhkf1]
Regards,
Adam