>>>>In a word, it appears not to work. 3.5x does work (we've been using it since it came out).
>>>>
>>>>The VaultIDE.dll was rewritten for 4.1, in order to work with VS2008 (they also have VSIP integration, but VaultIDE.dll gives the old style integration). I believe they implemented MSSCI 1.3, but SourceGear support hasn't gotten back to me yet on my request that they ask the developer if s/he knows of any changes that would have broken this functionality.
>>>
>>>Great.
>>>
>>>Is there any reason not to use Source Safe with VFP? I like Vault, but we already get SS with our MS Action Pack stuff.
>>
>>I've been using SourceSafe with my VFP projects for years.
>>
>>I use the VSS Client interface - NOT VFP integrated VSS functionality. Had too many instances of corruption with the integrated client.
>>
>>Other than that, it works great for me.
>
>Is VFP supported by VSS? Vault is not, though it works.

Yes.