Hi Stephen,

the keep-going option effects only the creation of individual tiles.

Your problem happens when the overview map is calculated, the problem

is not related to 3GB or 4GB, it is about  the limit in this single img file.

As I said you are probably putting too much information into your overview map,

to solve the problem you have to change your style or the overview-levels statement.

If you don't create files fort the PC you don't need the overview map, so maybe

use the option --no-tdbfile.  But this will also tell mkgmap to avoid the creation

of the ovm*.img files.

Gerd