IndustrialCraft² now has a Mantis Bug Tracker >>> http://bt.industrial-craft.net<<< for bug reports.
Mantis requires you to make an account, but submitting issues in the bug tracker is fairly easy and allows the IC2 dev team to easily track, list and fix bugs.
Things you must know before you make a bug report:
B1: Make sure you use the latest version of IC2 for the version of Minecraft you're using.
Also, only bug reports for IC2 2.6.* and 2.7.* MC 1.10.2 and 1.11.2 are accepted, if you have problems with older versions use the Support section of the forum.
B2: Search for information before posting anything. This includes recipes in JEI or any information that may be on the forum.
B3: The Bug Tracker is for Bugs, and bugs only! Discuss suggestions, game mechanics and complaints on the forum.
Rules for bug reporting
1: You have read B1-B3 and acknowledged them.
2: Make sure the bug you want to report was not already reported. If it was already reported, but you can give any additional information, add a note on that issue including your information. But do not create a duplicate issue.
3: 'Description' must include IC2 and Forge Version. ( Example: IC2 Version: industrialcraft-2-2.2.598 / Forge Version: 1.7.10-10.13.0.1207 )
4: For bugs that cause crashes, you must include logs of the crash.
5: Write a short and clear text for the 'Description' and 'Steps To Reproduce' to avoid confusion and reduce time spent by the developers reading long wall-o-texts.
Try using screen shots and/or videos for better explanation (especially on complex problems). Please also include the first version the bug appeared.
All bug reports that do not follow the rules will be closed.
Sorry, but reading the bug tracker everyday was taking a lot of time because of unnecessary or incomprehensible bug reports.
Time I would prefer to use in fixing real bugs and adding new features (I still have a long ToDo list).
Modified for a better understanding by SpwnX
Modified once again by imer to fix some spelling things
Added rule about duplicates by Aroma1997
Fixed link and updated versions by Chocohead