[syslinux] Problem booting bcdw with isolinux 3.11

[Zipf Christian]

I try to boot
Bootable CD Wizard (1.50z) by reanimatolog
http://bootcd.narod.ru/
with isolinux 3.11 with the following config

label 1
    kernel /bcdw/bcdwboot.bin

but it just gives me the following error
Image checksum error, sorry...
Boot failed: press a key to retry

It used to work fine with 3.10 and all prior versions.
Can anybody give me a hint on what needs to be changed.

thanks
christian