Please, update syslinux to 3.86.
Changes in 3.86
* chain.c32: fix chainloading the MBR of a hard disk (broken in 3.85).
* mboot.c32: report the boot loader name in the information structure.
* com32: set argv in a com32 module.
* core: add a workaround for a bug in Xen HVM older than version 3.3: disable halt on those platforms.
* Fix problems where certain operations in com32 modules would cause the core to believe the system was idle.
* MEMDISK: fix MBR detection when used with a DOSEMU header or an offset.
* MEMDISK: generate the mBFT checksum correctly.
Changes in 3.85
* gPXELINUX: updated to gPXE 1.0.0. gPXELINUX can now do NBP chainloading, and does not require a second DHCP.
* vesamenu.c32: unbreak the default "grey hole" background.
* We no longer have a built-in default of linux auto. Instead, if no DEFAULT or UI statement is found, or the configuration file is missing entirely, we drop to the boot: prompt with an error message (if NOESCAPE is set, we stop with a "boot failed" message; this is also the case for PXELINUX if the configuration file is not found.)
* chain.c32: support chainloading Grub4DOS; patch by Gert Hulselmans.
* New tool: sysdump.c32, can be used to produce system information for debugging via tftp or ymodem (serial port).
* vga=current on the Linux command line is now supported.
* chain.c32: support for Windows Recovery Console, via the cmldr= option.
* chain.c32: should now support loading NTLDR from different type media than loaded from.
* chain.c32: support chainloading to a FAT/NTFS partition with invalid "hidden sectors" via the sethidden option.
* memdisk: fix the mBFT ACPI table.
* vesamenu.c32: if the image is smaller than the screen, tile it across the whole screen.
* mkdiskimage: -s option for producing a sparse image.
* vesamenu.c32: support arbitrary resolution setting (beyond BIOS support) on some Intel-based video chipsets. This code is a modified version of the "915resolution" tool by Steve Tomljenovic; your mileage might vary.
Please also include the C isohybrid as described in FES ticket 15.
This will probably save some space on live images and it would be nice to know how much, early in F14 development.
F14 and F15 have syslinux 4.02 now, so this is moot.