Installing chmreader-linux_x86_64-gcc3-0.2.3.xpi into x86_64 Ubuntu 9.10 Firefox got message:
CHM Reader 0.2.3 could not be installed because it is not compatible with Firefox 3.5.5.
downloaded from http://sourceforge.net/projects/chmreader/files/chmreader/0.2.3/chmreader-linux_x86_64-gcc3-0.2.3.xpi/download
Any suggestions.