Look here: h**p://support.microsoft.com/default.aspx?scid=kb;en-us;Q317751
This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows XP service pack that contains this fix
In other words it is a bug that will be "hopefully" repaired in an up and coming service pack.
You "could" try running this command also: regsvr32 c:\windows\system32\zipfldr.dll /u. Apparently some people have had good luck using that.