ClickOnce - File accociations are lost upon progrmmatic updates to ClickOnce on Win 7 X64
File associations created for ClickOnce applications are lost only on Win 7 X64 bit machines upon a programmatic update.
Bug in ClickOnce due to Registry reflection disabled in Win 7.
Programmatic updates with ClickOnce run under Wow64 on Win 7 X64 and cannot write the registry information for the file associations under the 64 bit registry nodes.
Bug not fixed yet, workarounds involve either disabling programmatic updates for Win 7 X64 and have users upgrade the application from the installation URL. OR Release a X64 build for X64 bit machines.
Contributor : Ravi Shankar