Hello Marianne, Hello Sean,
thanks for bringing this post up again.
Yes, the mentioned workaround avoids the problem. +1
BUT: It is very annoying, that any component executed in the context of an ESRI 10.1 Add-In suffers from this behaviour. I am using an external assembly as connector to another application. This assembly also gets this twisted path, when called from an ArcMap 10.1 Add-In. Executed from any other source, the temp path is correct.
So this problem goes beyond the Add-In itself and therefore this or any other workaround sadly has to be implemented in every dependent component, too. IMHO this is a bug.
Kind regards,
Fossi