http://bugs.winehq.org/show_bug.cgi?id=17783
--- Comment #10 from James Andrewartha trs80@ucc.asn.au 2009-04-18 11:48:23 --- It's odd then that the SSL cert is accepted by native Windows and Linux Firefox 3, but when I grab the nssckbi.dll from the Firefox 3 zip at http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-mozilla1.9.0/ and put it in my wine_gecko directory, Steam still gives the sec_error_unknown_issuer error. Actually, running wine on that Firefox gives the error as well, so it's not a nssckbi.dll problem at all.