Is it only the two users?
If so I would have them log into the system on another local computer and see if the issue is resolved, if so I would delete their TD80 folder (this will be rebuilt the first time that they connect back to ALM so it is not a detrimental thing to do as it just clears the cache and correct strange issues as this). It is within the Users folder on their system (close internet explorer, open a windows explorer, search for the TD80 folder, and then delete it) Relaunch IE and connect to ALM and test if the issue is resolved.
I would also check with the users that they aren't using custom display settings that are not allowing the entities to be display because of sizing on the screen issues (as I have seen this many times before). If they don't haver any strange or custom display settings and it is the same issue logged into another computer then they may have an issue with their user account. I would then recommend you delete the account through Site Admin at the Site Users tab and then recreate the accounts and retest.
Everyone that has ever installed ALM on their system has a TD80 folder. It resides within the AppData folder which by default is hidden. The path on my local client used for testing is as follows (and should be similar for you with the exception of the user name account will be their actual username):
C:Users<local user account name>AppDataLocalTemp
By typing %tempo% into the Windows Explorer url bar it should take you directly to it. If it doesn't you may need to change the display settings on Windows Explorer to show hidden folders then you will be able to navigate to it.
Hope this helps,