mshtml.dll problem

Hi. My kiddies have been having trouble getting to their Webkinz site. The
main page will load, but the pop up page to log in will be a blank screen. I
have tried everything suggested from Webkinz and Microsoft, and nothing has
worked. I've reregistered some dll files, and found this message:
mshtml.dll was loaded, but the Dll register Server entry point was not
found. this file cannot be loaded.
I have IE 7, and all immediate uploads from Microsoft. I've searched for
anything I can on this, and hardly found anything. I hope I can get some
help here!
Do I have to reinstall mshtml.dll, or somehow fix the entry point in the
registry? Any advice would be immensely appreciated!!!
.