I am not positive that this is the cause of the issue, but you MAY be able to get rid of this issue by identifying the “User Agent” for Seamonkey as something else.
There is an “Add-on” for Seamonkey — see https://addons.mozilla.org/en-US/seamonkey/addon/user-agent-switcher/ – that will allow you to use Firefox or some other browser as the identification – at least for this page and you ought to be able to spoof it successfully. Worst case, tell it that you are running some recent version of Internet Explorer on Windows if nothing else will work.
Give it a try and see if this makes any difference and let us know for future reference. Thanks!