Hi,
Which version and build of C1FlexGrid are you currently working with?
I was not able to replicate the issue at my end using the latest build of C1FlexGrid at my end. The MouseCol property in the C1FlexGrid’s Click event returns the correct column index even if the grid is scrolled to the rightmost column in it. Please find a small sample application implementing the same attached and let me know if it helps.
In case you are using an older build of the control, please download the latest build from the following link and check if the problem still persists on using the same:
http://prerelease.componentone.com/dotnet20/c1flexgrid/2013-t3/C1FlexGrid.2_2.6.20133.800.zip
http://prerelease.componentone.com/dotnet40/c1flexgrid/2013-t3/C1FlexGrid.4_4.6.20133.800.zip
Thanks and Regards,
Pragati Kaushik