Loading large image and while it is loading press stop you get image contains errors.
This regressed between Mozilla1.4b and Mozilla1.4rc1

http://www.javaworld.com/javaworld/jw-07-1996/jw-07-classfile.html
Java drag select page scrolls up.

http://lxr.mozilla.org/seamonkey/source/editor/libeditor/html/nsHTMLEditorStyle.cpp#162

http://lxr.mozilla.org/seamonkey/source/editor/libeditor/html/nsHTMLEditor.h#751

http://lxr.mozilla.org/seamonkey/source/editor/libeditor/html/nsHTMLEditorStyle.cpp#1044

When switching tabs when links has focus and selection inside, the selection gets lost after you return.

Multiple drag drop inside html designmode iframe can go wrong. It can cause doubled pastes (assertions in debug build).

http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/editor/libeditor/html/nsHTMLDataTransfer.cpp&rev=1.108&root=/cvsroot#752
selection->Collapse(selNode, 0);
selection->Extend(selNode, selOffset);
works for editor, but not for textarea's inputs and so.
Cut and paste should not select the pasted text hereafter.

http://lxr.mozilla.org/seamonkey/source/editor/libeditor/base/nsEditorCommands.cpp

http://lxr.mozilla.org/seamonkey/source/editor/libeditor/html/nsHTMLDataTransfer.cpp#1399

http://home.houston.rr.com/billhopp/pickmain.htm
Focus bug

http://www.tiscali.nl/producten/adsl/smart.asp?rnaam=&mediacode=&retailercode=&activationcode=15804a

http://alloilpaint.com/hawaii/landscape/
Focus bug

Middle click doesn't support image map links that send also a coordinate.

http://lxr.mozilla.org/seamonkey/source/layout/printing/nsPrintEngine.cpp#1683