Tested on xp pro sp3.
All works fine.

file testbug:
$result = WriteValue ("HKEY_CURRENT_USER\Software\Blah","TestValue","4294967295","REG_DWORD")

Test1:
kix32-453.exe testbug.kix
result: ffffffff

test2:
kix32-460.exe testbug.kix
result: 7fffffff

Test3:
kix32-461b1.exe testbug.kix
result: ffffffff

Results tested on w2k sp4 Ger, xp pro SP3 Ger