strange compiler error

[ch0k3n]

My html form servlet imports a small package from my CLASSPATH,
but results in a strange compiler error. However the same package
was successfully tested by another small program.

Could someone tell me what this error means? Thanks!

C:\servlet>javac FormServ.java
sun.tools.java.CompilerError: invalid slot: 0: aload -1
This error possibly resulted from poorly constructed class paths.
at sun.tools.asm.Instruction.size(Instruction.java, Compiled
Code)
at sun.tools.asm.Assembler.write(Assembler.java, Compiled Code)
at sun.tools.javac.SourceClass.compileClass(SourceClass.java,
Compiled C
ode)
at sun.tools.javac.SourceClass.compile(SourceClass.java,
Compiled Code)
at sun.tools.javac.Main.compile(Main.java:567)
at sun.tools.javac.Main.main(Main.java:733)
error: An error has occurred in the compiler; please file a bug report
(http://j
ava.sun.com/cgi-bin/bugreport.cgi).
1 error

C:\servlet>