clstat is sometimes a real pain to work with as it requires a lot of things to 'just work' so to say.
Your cluster can be fine and
clstat doesn't respond. There's this handy note from ibm:
IBM Common issues causing clstat to malfunction
There's other resources / blog posts about getting
clstat talking again and I suggest digging into them. Gotta run to so can't post them all here right now.