Hi All, 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 files (1.1G, from 293 .img tiles), where it throws Exception in thread "main" java.lang.IllegalArgumentException at java.nio.ByteBuffer.allocate(ByteBuffer.java:328) at uk.me.parabola.imgfmt.sys.Directory.sync(Directory.java:176) at uk.me.parabola.imgfmt.sys.ImgFS.sync(ImgFS.java:230) at uk.me.parabola.imgfmt.sys.ImgFS.close(ImgFS.java:240) at uk.me.parabola.mkgmap.combiners.GmapsuppBuilder.onFinish(GmapsuppBuilder.java:119) at uk.me.parabola.mkgmap.main.Main.endOptions(Main.java:413) at uk.me.parabola.mkgmap.CommandArgsReader.readArgs(CommandArgsReader.java:126) at uk.me.parabola.mkgmap.main.Main.main(Main.java:127) r1724 and earlier works fine. Any thoughts? I've seen earlier threads with the same error, but hopefully narrowing it down to the specific commit helps. I've also tested my r1724 image on my eTrex and everything works fine, so the suggestion in one of the earlier threads that the file format only supports 256 sub-images isn't watertight. Cheers, Andy