solver - not always optimal solution ?

Hi all
Using solver add-in for the first time. The aim is to get the maximum possible profit from a price/quantity/marketing spent variation (quite complex, many formulas on the way to the "profit" cell but I hope it should work)

So far I tried it on easier example and seems ok. What worries is me: if everything works will it always be the optimal solution or only when all conditions are met? The article from MS website that I cite below concluded that it is not always the case ("acceptable solution")?
Can you try to explain the point from there for me ?

"What if there is more than one solution to the problem?

In the previous example, the Solver determined that you could sell 100 mochas, 175 lattes, and 100 regular coffees to reach your sales goal of $700. But you can also reach the $700 mark using a different product mix; for example, you could sell 94 regular coffees, 151 lattes, and 125 mochas to reach $700. (Using this mix, your revenue would actually be $700.75.) So, how did the Solver decide what the optimum product mix would be? The Solver simply started with the current numbers in the variable cells and adjusted them until it found an acceptable solution (subject to the constraints described in the previous example). This is why, if you use different starting values in the variable cells before you run the Solver, you can get different results from a problem with multiple solutions."

Thanks fot that previous reply. Has anybody experienced premium solver?
Does it also "get stuck" or returning not always optimal solution ?
Thanks