Stock/Mutual Fund transactions

[Phil Longstaff]

I'm trying to duplicate my current Quicken setup in GnuCash, along with
some changes (basically, a change in currency).  I am in the processing
of moving to the US, so I want most of my accounts to be set up with USD
as the currency.  However, I have some Cdn$ mutual funds in my
retirement funds.

My understanding (though I am not sure I've ever seen this spelled out)
is that I create a "Retirement" account, and under this, create a single
account for each mutual fund in my retirement account.  Is this correct?

My problem is that if I configure the mutual fund account to use USD, it
doesn't pick up prices downloaded in CAD (I've created a Finance::Quote
module to download Cdn$ mutual fund prices), even though the price
editor has the prices.  However, if the mutual fund account is in CAD,
then I can't create transactions properly.  If I want to enter a
purchase, Gnucash severely limits the set of possible accounts used to
balance the double-entry accounting.  It is limited to other accounts
which use the same mutual fund commodity.

How should I be setting this up?

Thanks for any help,
Phil