[SalesForce] RemoteAction Insert Error: “Please provide an id or sobjectType value”

I posted this to Twitter a couple of times but I'm still stumped.

I have an Apex class called "TestRemoteActionClass" with a method marked as a @RemoteAction that looks something like this:

@RemoteAction
public static List<sObject> insertRecords(List<sObject> records) {
    insert records;
    return records;
}

In my Visualforce page, I call it like this:

Visualforce.remoting.Manager.invokeAction(
    'TestRemoteActionClass.insertRecords',
    records,
    function(result, event) {
        console.log(result);
        console.log(event);
    }
);

Every time I try this, I get the following error back:

"Please provide an id or sobjectType value"

I understand the issue is related to the RemoteAction method taking a List as parameters, so it would make sense that the method needs some context to describe the SObjectType of the incoming list of records. If I change the "insertRecords" methods to take a concrete SObjectType (Account, Contact, etc), then it works fine.

However, I cannot figure out how to pass an "sobjectType" value with the parameters. I have tried the following as the "records" parameter with the same error:

[{"attributes":{"type":"Account"},"Name":"foo"}]
[{"attributes":{"sobjectType":"Account"}, "Name":"foo"}]
[{"sobjectType":"Account","Name":"foo"}]

In addition, I have tried numerous permutations of uppercase vs. lowercase combos for the 'sobjectType' parameter name. Still no luck.

Can anyone help? This issue is keeping me from creating a List "insert" call via RemoteActions, which would be huge to streamline things.

If this approach is just not possible, please let me know that too!