Incremental Upgrade Path from 6.5.1

Hi All

Does anyone know the correct/recommended incremental upgrade version path from 6.5.1 onwards?

I have Domino 6.5.1 running on W2003 server and have tried the 6.5x to 6.5.2 incremental and the 6.5.2 incremental both of which fail with the error message that they don’t recognize the correct version of Domino.

Is there something unusual about the incremental upgrades from 6.5.1 I should be aware of?

Thanks in advance

Mark