Description of problem:
While changing 'Boot options|Run Once -> Linux boot options' to include only path to initrd and then clicking OK (not defining kernel filename path), both kernel path and initrd path textboxes got orange borders. Hoving with mouse cursor over these textboxes there is _NO_ informative text displayed. I would expect an informative msg like 'Kernel path must be defined' or something logically relevent as you cannot use initrd without kernel.

Version-Release number of selected component (if applicable):
sf5

How reproducible:
100%

Steps to Reproduce:
1. have a linux VM
2. 'Boot options|Run Once -> Linux boot options' (check both ways!)
3. put path to initrd but do _not_ put path to kernel
4. click OK
5. hover with mouse over "orange" textboxes
  
Actual results:
no informative msg

Expected results:
some relevant informative msg

Additional info: