There are a number of third-party programs that have been shown to cause problems with Opus, or cause problems for which most users' natural reaction is to blame Opus.
Falling mostly into the "system tune-up", anti-virus and anti-spyware categories, they can cause symptoms ranging from mysterious delays in normal functions to graphics glitches and outright crashes.
We will aim to maintain a list of known programs here. Although we are not making any particular claims about the quality (or lack-thereof) of these programs, the problems they have caused with Opus do tend to suggest that far more effort has been put into marketing these applications than into actually developing them and making them work properly.
We will add to this list and flesh out the details over time:
May cause Opus to crash (e.g. during shut-down) and/or to have unwanted window-order behaviour. Add Opus to the list of exclusions so that Filebox eXtender does not interfere with it.
Opus and Nero generally work together without issue (indeed, most of the developers and admins here use Nero quite happily) but it seems there are problems with the installers for some versions of Nero 7 which break parts of Windows which Opus depends on:
1) We have a report that installing Nero 22.214.171.124 can break Opus (among other things). This appears to be fixed by newer versions of Nero, with 126.96.36.199 said to work. See this thread for more information.
2) Another problem which appears to be caused by some versions of the Nero 7 is discussed in a separate FAQ, Unable to drag new buttons from Customize to Toolbars. This problem (that some Nero 7 component installers remove the COM IStream details from the registry) can also break other parts of Opus and other programs, but toolbar drag & drop is where people usually notice it first. It can usually be solved by simply double-clicking the registry file in the separate FAQ.
Caused a strange problem relating to left-over drive letters when USB drives were removed and re-inserted. Apparently fixed in current version.
Causes strange delay when double-clicking on a drive in the My Computer virtual folder in an Opus Lister. Apparently linked to the "SMSystemAnalyzer.exe" module.
Causes many problems including loss of registration information and inability to launch external programs. Most problems can be fixed by telling Zone Alarm to not interfere with Opus. See this FAQ entry for more details.