A colleague of mine is unable to use Chrome and found the page borderline unusable with Mozilla.
Don't have time to look into it at the moment, but a possible workaround would be to detect FF and either disable the fixed header, or provide a shim (eg, move it manually with JS rather than depending on the position: fixed css property).
May or may not be related to this long-standing bug. (Related SO discussion)
A colleague of mine is unable to use Chrome and found the page borderline unusable with Mozilla.
Don't have time to look into it at the moment, but a possible workaround would be to detect FF and either disable the fixed header, or provide a shim (eg, move it manually with JS rather than depending on the
position: fixedcss property).