I guess yes, the random numbers have something to do with the internal clock.
Besides, this is taken from the on-line help for version 7.0.1
(sorry, I don't have your version)
Return RAND to its default initial state.
rand('state',0)
Initialize RAND to a different state each time.
rand('state',sum(100*clock))
Save the current state, generate 100 values, reset the state,
and repeat the sequence.
s = rand('state');
u1 = rand(100);
rand('state',s);
u2 = rand(100); % contains exactly the same values as u1
.
.
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http://www.matrixlab-examples.com