Custom Action Error

[sigh71]

I'm trying to make a custom action, and when it runs i get this error

Unable to convert property ServerName (value: asgard) to Boolean

Its a c# action, but i don't think its getting to my actual code in the dll.
Here is my action file.
i can provide the c# code if needed.
I'm trying to make a custom action to start and stop vmware virtual servers.

<action Name="VMWare Action">

<GUI Category="Server"
Description="Manage VMWare virtual servers"
Bitmap="NETAction.bmp">

<Tab Name="VMWare">
<Field Name="ServerName"
Type="Edit"
Description="VMWare GSX Server Name"
Width="200">
</Field>
<Field Name="UserName"
Type="Edit"
Description="GSX Login Name"
Width="200">
</Field>
<Field Name="UserPassword"
Type="Edit"
Description="GSX Password"
Width="200">
</Field>
<Field Name="MachineName"
Type="Edit"
Description="Virtual Machine Name"
Width="200">
</Field>
<Field Name="ServerAction"
Type="Combo"
Description="Virtual Machine Action"
Width="200"
DefaultValue="1">
<ListData>
<ListItem Text="Start"/>
<ListItem Text="Stop"/>
</ListData>
</Field>
</Tab>
</GUI>

<Build>
<ActionComponent>VMWareAction.Test</ActionComponent>-->
</Build>
</action>