From our source control guy at work (we're using UCM ClearCase, I don't know if this issue exists in Base ClearCase):
Tool: IDEA from IntelliJ - Clearcase plugin
Problem: Missing code in an element
Environment: Windows 2000 / UCM - Snapshot views
For those of you using IDEA, you should be aware that the Clearcase plug-in is missing a fairly important integrity check in its Check-out action.
A recent issue surfaced where a developer checked out an element using the plug-in, only to find the version that they checked out was not the most current on the stream. The result was seeing an older element that was missing code from a recent check-in.
If you are using snapshot views, this can happen if you do not perform a view update prior to checking out the element(s). If you perform an update after you have checked out elements, the elements are checked-out against the view's prior state - prior to the update, and might not reflect the most recent (/main/LATEST) version in the stream.
Cause: Element Check-out against stale view.
Within the IDEA plug-in, a class method is called within the class file "CheckOutOrHijackAction" . The method called performs only an 'isactive' VCS check -- that is, to see that there's actually a running copy of Clearcase active on the local machine. It does not perform any stream/view integrity check to see if there are more recent versions on the stream compared to the version presently known in the view, as does the Clearcase GUI.
I've emailed the plugin author with this information. Again, I don't know if this affects base ClearCase (which is what he's using) as well, or if it's just a UCM ClearCase thing.