I'm having a strange problem with Eclipse 3.0 running on Windows 2000
v5 sp4 under JDK 1.4.1_03.

I've been successfully working on a project all week.  It's got an Ant
build.xml that can compile and build the app without any compilation
errors at all.

However, just this morning I got 330 "problems" showing up in the
Problems console window.  All of them are for classes in a single
package.  The messages are all along these lines: "CommandException
cannot be resolved or is not a type".  The CommandException is in the
same package as the class reporting the problem.  The "quick fix",
according to Eclipse, is to import CommandException into the offending
class, but that shouldn't be required since they're already in the
same package.

If I exit Eclipse and run Ant in a command shell, the code compiles
and builds perfectly.  It builds fine inside Eclipse, too, but the
Problems don't go away.  I've refreshed the project several times, to
no avail.

None of this showed up yesterday.  All I did was fire up Eclipse to
start work for the morning.  Why all these problems, and what do I
have to do to get Eclipse to recognize that all is well? - MOD