TRig simplifications failing



   
I am having some trouble when I try to simplify certain trigonometic
expressions 

For instance: after a loop using rotation matrices I obtain a matrix
with elements like


	       [ COS(q4 + q3 + q2 + q1) + COS(q4 + q3 + q2 - q1) ]
	       [ ----------------------------------------------- ]
	       [		        2			 ]
	       [						 ]
(D46)  Col 1 = [ SIN(q4 + q3 + q2 + q1) - SIN(q4 + q3 + q2 - q1) ]
	       [ ----------------------------------------------- ]
	       [		        2			 ]
	       [						 ]
	       [	        SIN(q4 + q3 + q2)		 ]

but I could not obtain a simpler expression like

[ cos(q4+q3+q2)*cos(q1)]
[ sin(q4+q3+q2)*cos(q1)]
[ sin(q4+q3+q2)        ]

which I intend to make another substitution like

[c234*c1]
[s234*c1]
[s234   ]

as the process fails at the first time the result becomes incredibly
large.