You may need to validate the name of your project in .project
file, which is the project description file.
Here's a link: http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fmisc%2Fproject_description_file.html
Here's a typical .project
file:
<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
<name>MyProject</name>
<comment></comment>
<projects>
</projects>
<buildSpec>
<buildCommand>
<name>org.eclipse.jdt.core.javabuilder</name>
<arguments>
</arguments>
</buildCommand>
</buildSpec>
</projectDescription>