New batch-add interface doesn't work on all server setups. Users who have issues with it should use the classic interface instead.
Page tabs in user manager don't behave in the same way as other tabs
Resizing gif/png with transparent background doesn't preserve alpha info
Wrong charset in emails sent from coppermine
Thumbnail sizes over 120px causes edit fields to run over its edge
No album thumbnails for albums that contain only pics linked by keyword
Crop/rotate doesn't work with GD1
Rotate causing distorted image for large files
<object><param></param></object> construct for multimedia files doesn't validate but is needed for backwards compatibility
EXIF and IPTC information are lost when rotating
Discrepancy between Coppermine internally using utf-8 and IPTC currently one supporting iso-8859-1. Subsequently, non latin characters like accented chars or Umlauts get distorted
Album created using XP publisher despite upload failure
No category thumbnail for user galleries and categories that don't contain albums with pics in it, but only sub-categories
Film strip may change its height when navigating if thumb dimension is set to 'width'
Some rounded corner effects of the curve theme won't work across-browsers, but are browser-specific. They will not work in IE mainly. The browsers that can't display rounded corners will display "normal" corners.
Album moderator feature not clearly documented and therefore disabled (thread)
Category thumbnails appear larger than expected if thumb aspect is set to "exact" for the thumbnail setting "Use dimension" (thread)
If you allow guests to upload files to your gallery, they won't be able to add file details. This feature has been disabled as it's not possible to identify the user without fail (see thread). Additionally it may attract spammers to add textual content to your gallery. If you want to enable that feature anyway, find Coppermine's configuration table in the database and change the value of allow_guests_enter_file_details to '1'.