[XeTeX] lotus linotype and quotation marks

[talazem at fastmail.fm]

Dear all,

I'm using XeLaTeX (with memoir, fontspec, & polyglossia). I have typeset my document in Lotus Linotype. The problem is that the quotation marks I have typed in are not appearing in the output. When I switch the font to Scheherazade, the quotation marks appear correctly.

I am sure it is a simple matter of which I am ignorant, but any help would be most appreciated.

Kind regards,
talazem