Does anyone know why this code goes into an endless enumloop on Windows 98, but not on NT/2000/XP

This code works fine on all the NT platforms, but goes into an endless loop with Windows 9x, CTRL-C won't break out of it either, but it will end task or if using DEBUG you can quit it.

code:
Break On
$UpdateCustom=UpdateDictionary()

Function UpdateDictionary()
$HKLMSF = "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
$HKLMSMWCV = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion"
$HKLMAppPaths = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths"
$app = "winword.exe"
$path = readvalue("$HKLMAppPaths\$app","")
$WordVer = val(getfileversion("$path","Productversion"))
$WordVerFull = GetFileVersion("$path","Productversion")
$FileToCopyLocation="\\sm-cag-fp10\logs\"
$FileToCopy="WDICustom.dic"
$Find		= "WDICustom.dic"
$EnumRegKey	= "HKLM\Software\Microsoft\Shared Tools\Proofing Tools\Custom Dictionaries"

If KeyExist($EnumRegKey)
		$Index = 0
		Dim $ValueName[100], $ValueData[100]
		 
		While @ERROR = 0
			$ValueName[$Index] = ENUMVALUE($EnumRegKey, $Index)
			$ValueData[$Index] = READVALUE($EnumRegKey, $ValueName[$Index])
			If $ValueData[$Index] = $Find $Found = 1 Endif
			If @ERROR = 0 $Index = $Index + 1 Endif
			If $Index = ubound($ValueName)
				ReDim Preserve $ValueName[$Index+100], Preserve $ValueData[$Index+100]
			Endif
		Loop
		 
		$Index = $Index -1
		ReDim Preserve $ValueName[$Index], Preserve $ValueData[$Index]
		 
		If Not $Found
			$nul = WRITEVALUE($EnumRegKey, val($ValueName[ubound($ValueName)])+1, $Find, "REG_SZ")
		Endif
		Return
Endif
Return
Endfunction