I've run into an issue with problems with compiler when spaces occur in 
directories.  Here's the error message I'm seeing:

javac: invalid argument: C:\Documents
Usage: javac <options> <source files>
where possible options include:
  -g                        Generate all debugging info
  -g:none                   Generate no debugging info
  -g:{lines,vars,source}    Generate only some debugging info
  -O                        Optimize; may hinder debugging or enlarge class file
  -nowarn                   Generate no warnings
  -verbose                  Output messages about what the compiler is doing
  -deprecation              Output source locations where deprecated APIs are 
used
  -classpath <path>         Specify where to find user class files
  -sourcepath <path>        Specify where to find input source files
  -bootclasspath <path>     Override location of bootstrap class files
  -extdirs <dirs>           Override location of installed extensions
  -d <directory>            Specify where to place generated class files
  -encoding <encoding>      Specify character encoding used by source files
  -target <release>         Generate class files for specific VM version
Errors compiling.

This happens when I right click on the filesystem and choose build all or 
compile all.

Source filesystem (internal cvs):
C:\Documents and Settings\erik\My Documents\dev\java\gef\cvswork\gef\src

Target directory:
C:\Documents and Settings\erik\My Documents\archive\dev\java\gef\build