Hi Andy
I realised I was having problems with the newest stable and not with an older version, so I went back through and did some bisecting. r1725 appears to cause issues for me when generating large gmapsupp.img
Well that is very interesting as that change is directly about creating gmapsupp.img files. It originate from the following: http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2010q4/009328.html Looking at this again, I think that although the original code is 'obviously' wrong, the new code is not correct either. It should be Dirent.ENTRY_SIZE instead of DirectoryEntry.SLOTS_PER_ENTRY. And the assert should definitely be there. There are two reasons for that. 1) I don't know that numbers other than 1 are allowed. 2) The rest of the code is written to make it 1. If that code is failing we need to know about it. Attached patch is what I think it should be. ..Steve