How is this possible? This run smoothly in Maple14!!!

eqts:=diff(u(x),x$2)=-M(x)/EI;
                     d  / d      \     M(x)
                    --- |--- u(x)| = - ----
                     dx \ dx     /      EI 
cnds:=u(0)=0,u(l)=0;
                       u(0) = 0, u(l) = 0
#M:=x->if x<=l/2 then P/2*x else -P*(x-l)/2 end if;
M:=x->piecewise(x<=l/2,P/2*x,-P*(x-l)/2);
              /    1    1        1          \
x -> piecewise|x < - l, - P x, - - P (x - l)|
              \    2    2        2          /
dsolve({eqts,cnds},u(x)):
assign(%):
u(x):=simplify(u(x));
Error, (in dsolve) invalid input: eval expects its 2nd argument, eqns, to be of type {integer, equation, set(equation)}, but received C_val
Error, invalid left hand side in assignment