When I step through the following code, `report` on the second line is null.
However, the third line generates a NullReferenceException.

```
member this.setTaggedResearchReportList (index : int) (taggedResearchReport : TaggedResearchReportUIVO option) =
    let report = Option.get(taggedResearchReport)
    if not(report.Equals(null)) then
        // do some stuff here

```

Why is that, and what can I do to avoid it? Thanks!

Added later:
------------

Here's the line that calls `this.setTaggedResearchReportList`:

```
getMostRecentTaggedResearchReportForSecurityId (item.id) (new Action<_>(this.setTaggedResearchReportList 0))

```

Here's the `getMostRecentTaggedResearchReportForSecurityId` method:

```
let getMostRecentTaggedResearchReportForSecurityId (securityId : int) (callbackUI : Action<_>) =
    getSingleRPCResult<JSONSingleResult<TaggedResearchReportUIVO>, TaggedResearchReportUIVO>
        "TaggedResearchReportRPC"  
        "getMostRecentResearchReportForSecurityId" 
        (sprintf "%i" securityId)
        callbackUI
        (fun (x : option<JSONSingleResult<TaggedResearchReportUIVO>>) ->
            match x.IsSome with
                | true -> Some(Option.get(x).result)
                | false -> None 
        )

```