Vista - Click-Once deploy error after updating IE6 to IE7

We have an app (VS 2005, C#) that we have been running for over two years
with out issue, but when we upgraded our client PCs to IE7 (from IE6), most
had an issue with running the app. When the user tried to start the
program, they receive an error (Unable to start application).
If I look in the log I see the following error:

PLATFORM VERSION INFO
Windows : 5.1.2600.131072 (Win32NT)
Common Language Runtime : 2.0.50727.3082
System.Deployment.dll : 2.0.50727.3053 (netfxsp.050727-3000)
mscorwks.dll : 2.0.50727.3082 (QFE.050727-3000)
dfdll.dll : 2.0.50727.3053 (netfxsp.050727-3000)
dfshim.dll : 2.0.50727.3053 (netfxsp.050727-3000)


ERROR DETAILS
Following errors were detected during this operation.
* [10/27/2009 3:36:24 PM] System.Runtime.InteropServices.COMException
- The referenced assembly is not installed on your system. (Exception from
HRESULT: 0x800736B3)
- Source: System.Deployment
- Stack trace:
at
System.Deployment.Internal.Isolation.IStore.GetAssemblyInformation(UInt32
Flags, IDefinitionIdentity DefinitionIdentity, Guid& riid)
at System.Deployment.Internal.Isolation.Store.GetAssemblyManifest(UInt32
Flags, IDefinitionIdentity DefinitionIdentity)
at
System.Deployment.Application.ComponentStore.GetAssemblyManifest(DefinitionIdentity
asmId)
at
System.Deployment.Application.ComponentStore.GetSubscriptionStateInternal(DefinitionIdentity
subId)
at
System.Deployment.Application.SubscriptionStore.GetSubscriptionStateInternal(SubscriptionState
subState)
at
System.Deployment.Application.ComponentStore.CollectCrossGroupApplications(Uri
codebaseUri, DefinitionIdentity deploymentIdentity, Boolean&
identityGroupFound, Boolean& locationGroupFound, String&
identityGroupProductName)
at
System.Deployment.Application.SubscriptionStore.CommitApplication(SubscriptionState&
subState, CommitApplicationParams commitParams)
at
System.Deployment.Application.ApplicationActivator.InstallApplication(SubscriptionState&
subState, ActivationDescription actDesc)
at
System.Deployment.Application.ApplicationActivator.PerformDeploymentActivation(Uri
activationUri, Boolean isShortcut, String textualSubId, String
deploymentProviderUrlFromExtension, BrowserSettings browserSettings, String&
errorPageUrl)
at
System.Deployment.Application.ApplicationActivator.ActivateDeploymentWorker(Object
state)

COMPONENT STORE TRANSACTION DETAILS
No transaction information is available.

I have searched on the net but the only solution I have found is to delete
the %userprofile%\Local Settings\Apps folder.

This worked fine, but I am having to do this over and over for the same
users. Is there a better solution?

Thanks for your time,

Tim