Solver changing restrictions by itself

I am using Excel Solver to solve an LP problem. However, every time I add a constraint involving multiplication or division, the Solver modifies the constraint on its own. What could be happening? For example, two cells that will vary in my problem are A1 and A2. When I add a constraint like A1 <= 2*A2, it changes this constraint to something completely different, involving different cells. I am sure that the problem is feasible even with the constraint I am trying to add! Any ideas?