Sigh!

[MSpagni]

When you asked for the registry data I exported the whole "ExamDiff Pro" and the .reg file contains all the relevant data.
I find surprising that your "export" doesn't.
A buffer too small?

[psguru]

See my answer about the "reg export" command. EDP simply uses it, so whatever it does on a particular Windows build, that will be the result of Export Settings.

[MSpagni]

The difference is between "reg" (command line) and "regedit" (GUI).
Indeed, while "regedit" exports everything, "reg" can't export keys so big (limit of 64 kb per key? Just a guess.)
So the culprit is the windows (32) command "reg".

Now the workaround is simple (at least for me).
And you can hope not to have too many customers so P.I.T.A.

Thank you very much for your patience.

[psguru]

It could be a combination of XP and 32-bit. I wonder how it would behave, say, under 32-bit Vista, although perhaps not many are out there.

[psguru]

Just to close this subject (for now?), apparently the following two commands do the same thing:

reg export "HKCU\Software\PrestoSoft\ExamDiff Pro" c:\temp\dump2a.reg
regedit /e c:\temp\dump2b.reg "HKEY_CURRENT_USER\Software\PrestoSoft\ExamDiff Pro"

However, the second one does produce the full key export on 32-bit XP, whereas the first may not. We can potentially switch EDP to use the second option, if the problem becomes a real PITA for multiple users. Except that all Microsoft docs suggest the first option, and the second is kind of an undocumented approach that seems to be a leftover from Windows 98(?) days.