Not able to check out files with long names in ClearCase Explorer

I am not able to find checkout option for a file when I right click on it in ClearCase explorer while the option is available for rest of the files. The only difference is that the file I want to check in has a very long name ( I am using Windows ). While I am able to check in via cleartool commands, it isn't possible from front end ( CC explorer) Is there any way to check out such files from CC explorer?

There are two possible causes for a checkout unavailable:

• the path of the file itself is too long (combined with the long filename, more than 256 characters): a subst command can help shorten the path.
• or the file is already checked out.

A cleartool status can help distinguish between those two cases.
And a cleartool lsvtree -graph aFile (replace aFile with your long filename) can help see the file history and see if it is checked out (reserved or not) in another view.