This problem persists (still there in April 2013 with version 1.5.22). 8000+ warnings logged after only two page accesses...
Per another bug (http://forum.coppermine-gallery.net/index.php/topic,71384.msg347009.html#msg347009
) some of the undefs were once fixed but not all. As the author of that bug said, it would really be better to fix the code to avoid referencing undefined variables.
Yes, I know I could disable seeing php warnings in served pages, but they are helpful in a test environment (a private web server) where all other software is warning-clean if there is nothing I need to respond to. But even if the only problem was clogging up the apache error.log it would be inconvenient, because it makes it more difficult to check if there is anything which actually needs admin attention.
In 1.5.22, the problem areas seems limited to the following places in the code:
Undefined index: no_modification_check in include/versioncheck.inc.php on line 425
Undefined index: txt_modified in include/versioncheck.inc.php on line 474
Undefined index: no_modification_check in include/versioncheck.inc.php on line 312
Undefined index: txt_missing in include/versioncheck.inc.php on line 777
Undefined index: no_modification_check in include/versioncheck.inc.php on line 786
I hope the above is helpful