Question: Warning, solutions may have been lost

>restart;
v1 := evalf(30*Pi/(180.));
v2 := evalf(120*Pi*(1/180));
r1 := 600;
r2 := 1800;
                                0.5235987758
                                 2.094395103
                                     600
                                    1800
>solve({r1 = a(1-e^2)/(1+e*cos(v1)), r2 = a(1-e^2)/(1+e*cos(v2))}, {a, e});
Warning, solutions may have been lost

I've tried doing this in 1d and 2d input modes to the same result.  When i tried fsolve it simply regurgitated the input after substituting variables.

fsolve({r1 = a(1-e^2)/(1+e*cos(v1)), r2 = a(1-e^2)/(1+e*cos(v2))}, {a, e});

         / /           /       2\                    /     2\     \         \
         | |          a\1 - e /                  a\1 - e /     |         |
   fsolve|< 600 = ------------------, 1800 = ------------------ >, {a, e}|
         | |      1 + 0.8660254037 e         1 - 0.5000000005 e|         |
         \ \                                                         /         /

  I don't know what's causing it and would love it if it would work.  any help would be greatly appreciated.