You can report any kind of bug related to Pd, including documentation, the website, libraries, etc. Its just a web form that you fill out and submit. Please provide as detailed information as possible including which operating system (OS), CPU type, specific hardware, and the exact distro and version of Pd itself, etc. For example:

 Pd version 0.41.4-extended
 Mac OS X 10.5.7/Intel
 built-in sound

• report any bug here: http://bugs.puredata.info

If you think the bug is specifically in Gem, then please report the bug to the Gem bug tracker:

• http://bugs.gem.iem.at