The above problem arises with custom eclipse installation and due to updated version of subclipse.
You have to install the older version of subclipse manually.
For this i have done as following:
Under Help menu click "Install New Software..."
Select "http://subclipse.tigris.org/update_1.6.x" from the drop down menu
If URL of any other advanced version of are available change it to look as above.
Check the options selected are sensible e.g. "Hide items that are already installed"
Click "Select All"
Click Next/Finish through to completion.
After finishing the installation,under windows menu go to preferences,click on Team and on SVN.
Now change the client from Java HL to SVN pure kit.
That's it.
This resolved problem for me