I recently worked on making my "tree menu":http://www.treemenu.com/ work with Opera 6 & 7 and noticed that v7 died with an error while trying to grab the frame names in the parent frameset. This is a problem I've never experienced with other browsers except Opera v5, and in that case I was able to fix it by letting the parent frameset's onload-event handle startup.
This time around I couldn't use that workaround since tests showed the parent frameset is finished loading and therefore doesn't trigger the onload event. In any case I'm not happy with the fact that no properties are available before the document is finished loading, so I made a little "testcase":/javascript/files/frame-delay-test.html available and submitted a bug report to Opera.
The testcase is pretty simple. A frameset contains two frames of which one has an onload event handler trying to access the name of each frame of the parent frameset. To make things difficult the second frame links to a small CGI-script that has delayed output by ten seconds. There's a second script found in the first frame, which calls a second attempt at getting the frame names after fifteen seconds.
I've tested it with Opera 7.11, Galeon 1.2.7 and Konqueror 1.3-13 Red Hat on Linux, Opera 7.20b7, Opera 6.01, MSIE5.5 and Mozilla 1.4 on Windows. Opera and Konqueror fail to get the frame names on the first attempt, but they both get them on the delayed attempt.
Opera 6.01 dies silently, while in Opera 7 the error message is available in the JavaScript console. I'm not experienced with Konqueror so I don't know if it reports errors anywhere.