Hi Finn,
Glad that fixed it. Since turning on "Exchange Rate Adjusted" did not fix it, you must have one or more investment that is not getting exchange rate adjusted and is in a different currency. It is likely that one of your exchange rate type investments is the reason. This is from the online help:
Investments assigned to an exchange rate and investments of type "Exchange Rate" are not adjusted with View / Exchange Rate Adjusted. It is recommended to assign such investments to the default currency, so that if/when they are included in a report, they do not cause (na) values due to summing across currencies.
If you correct these investment's currency assignment then you should be able to turn back off that option to allow summing across currencies, and still get your totals reported when exchange rate adjusted is on.