Hi Michael, I just disabled the sticky header menu on the demo and can't see any problem on my android/chrome mobile device... can you PM with more details, type of mobile device + browser used, your dev URL etc. Thanks.
If you're using Safari, it might be a CSS issue.
On another matter, there was a minor issue with the /skin/reboot/customer/bread_crumbs.tpl file, which has been fixed in the
latest zip file.