[news.eclipse.platform] Weird behaviour in Tomcat projects in 3.0.1

["Rhino" <rhino1@xxxxxxxxxxxxxxxxxxx>]

I am using Eclipse 3.0.1 on Windows XP along with Tomcat (5.0.28) and
Sysdeo.

Today, something odd happened with respect to Eclipse: two of my several
Tomcat projects have unusual errors. According to the 'Problems' list:
- Project Foo is missing required source folder: 'work'
- The project cannot be built until build path errors are resolved

When I look at the Properties for the two projects (both have identical
errors), the Java Build Path page says: Build path entry is missing:
/Foo/work.

I have no idea where the work folders went for these two projects; this
problem only started happening today. Nevertheless, I thought I could solve
it easily by simply creating the work folder again. However, when I try to
create a new source folder named 'work', I get the message: The folder is
already a source folder.

Eclipse and/or Sysdeo seem to be trying to have it both ways: on one hand,
it complains that the folder is not there but on the other hand it admits
that the folder is there.

How do I resolve this problem?

Also, does anyone have any idea why it just started happening today but only
affected two of my 11 Tomcat projects? I can't think of anything I did today
that would cause this problem; I haven't touched anything in those two
projects or Tomcat all day.

-- 
Rhino
---
rhino1 AT sympatico DOT ca
"There are two ways of constructing a software design. One way is to make it
so simple that there are obviously no deficiencies. And the other way is to
make it so complicated that there are no obvious deficiencies." - C.A.R.
Hoare