If you feel that something does not work as it should, the most effective way how to proceed is to post a message in the forum. The usual ethics apply here the same way as on most of the forums all over the Internet: Before posting, check if the problem isn't already reported. Please, make sure that you are posting to the correct forum section. If you experience problem with library, make sure to post to U++ Library support. Problems with TheIDE should be reported to U++ TheIDE. Note that some sections have sticky posts, please read them before posting, they usually contain important information.
You should always provide the information about your system, as it often helps when reproducing your problem. Usually writing down the version of U++, your operating system and compiler is enough. If the problem is TheIDE related, include also the version of TheIDE - it can be found in the About-box (Assist > About ...). In some special cases we might ask for more details if it is necessary.
Also please DO NOT post bugs to Bugs (& fixes) forum directly. Use the category best describing your problem, they will be moved later if necessary.
Whenever possible, please add a simple piece of code (a "testcase") that demonstrates the problem to your report. When the developers know how to reproduce the problem, there is much higher probability that fix will be released soon. In simple words: Problem reproduced is usually a problem solved. If the testcase is single file only, just post the code into the forum post. If it is more complex, you can use .zip attachment.
One picture is worthed thousand words, as the old saying goes. If you experience any kind of rendering problems, including a screenshot helps very much and saves you some typing.
If you are find a bug and you also happen to be capable of solving it, we would be very thankful if you post your solution. The same also applies if you find a solution to bug reported by someone else.
If the patch changes only small part of code, the preferred method is to post only changed functions or classes in the post text. To make it easier for people reviewing the patch, you should also write in which files the changed code resides. If there are more files affected, the best is to simply post all changed files in .zip as attachment.
Sometimes people ask why we don't use *.diff or *.patch files. The reason is very simple: U++ is multiplatform framework and there exist many different formats for diff/patch. So while these utilities were initially created to save work, it actually sometimes acts just opposite. That said, we don't refuse patches in diff format. We will try to apply them, but if they are not compatible with the tools we use, we will ask you to provide the changes in different format. So to save work on both sides, we prefer posting the changed code or whole files.