Memory issues in MFC (/clr) application

Hi,
          We have an MFC application with /clr option, in that we are using a third party grid control, which is designed and developed in C#, we need to load data from VC++ to grid control(which includes some images also), but application crashes after reaching certain max. counts(say more than 2 lakhs) of rows,  what is the cause of this memory issue, and how to fix it.
Thank you,