Changing TVI_FIRST fixes the problem for me with 64-bit (but I didn't try 32-bit yet!):
sub TVI_FIRST () { -0x0FFFF }

Here is its definition in CommCtrl.h:
#define TVI_FIRST   ((HTREEITEM)(ULONG_PTR)-0x0FFFF)

In reply to Re: x64 Win32::GUI TreeView broken, question and "fix" included by coicles
in thread x64 Win32::GUI TreeView broken, question and "fix" included by tomsell

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