I have compiled the latest svn available, currently 10186, in order to test it thoroughly.
The first thing I have tried was to comment multiple lines using Ctrl+Shift+C. It does not work; it goes to DoxyBlocks tab and add the following line:
HTML Help not found at /home/stefanos/Projects/ANSI_C++/GeneralCode/doxygen/GeneralCode.chm.
Can anyone try to reproduce this? Cheers.