[Bonmin] Bonmin failing to deliver solution to GAMS (or failing to calculate solution?) in convex MINLP

[Juan Jose Galvez]

Hello,

I'm trying to solver a number of convex MINLP instances of a problem  
using Bonmin through GAMS and am frequently getting this error message  
when bonmin finishes:

Warning: Optimal value of NLP subproblem differ from best MINLP value  
reported by Bonmin.
Will not replace solution, dual values will not be available.

When this happens, GAMS does not receive the last feasible point (and  
supposedly optimal solution) found by bonmin. So first of all I'm not  
sure if bonmin is correctly calculating the solution in these cases,  
and if it is, it's not sending the solution to GAMS. Is there any way  
to solve this or get around it?

Regards,
Juan