why can the feasible problem not find solution

[aozmen296]

Hello All,

I have a problem. I have a equation in my code. SUM(k$(ORD(k)>1),b(k)) =l= 28;

If i run the code this way, sometimes my code gives "0" as objective function. But i know that the answer can not be 0. The answer must be different from "0".
Normally in a problem that gives "0", if i change the equation as SUM(k$(ORD(k)>1),b(k)) =e= 28; that gives me a solution different from "0".
And also i have M (big M) in my code. I made some calculations for M at my problem I am writing this as M = 1e8. In some problems that objective function gives me "0", i am changing M (big M). For example if i change M from M= 1e8 to M=4e7, i am taking an answer different from "0".

I am 100% sure about my problem and equations. There is not infeasibility or "0". Why GAMS give me sometimes "0". And If i make some small changes, i take answer different from "0".
Do i have to use gams option file or anything, can you suggest me something..

Thank you.

[bussieck]

Without something to reproduce there is nothing to do. -Michael