Component not auto-registered under Windows98

I have a relatively simple component that installs ok on Firefox 1.0PR
(Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20040913
Firefox/0.10) running on WinXP, but when I install it on the same
version of Firefox running on Windows 98 (same goes for WinNT4), it
doesn't get registered, and when I try to access it, I get a
javascript error that goes :

Components.classes['@moofoobar.com/mycontractid'] has no properties

I tried calling regxpcom manually, and it still doesn't get
registered. I put some debug output in the registration function to
notice that it simply does not get called.

I have the following nsModuleComponentInfo in my DLL code :

static const nsModuleComponentInfo components[] =
{
	{ "myMooFooBarComponent",
	myMooFooBarComponent_CID,
	myMooFooBarComponent_ContractID,
	myMooFooBarComponentConstructor,
	myMooFooBarComponentRegistration,
	myMooFooBarComponentUnregistration
	}
};
NS_IMPL_NSGETMODULE(myMooFooBarComponent,components)


The component works perfectly and gets registered when installed on a
WinXP or Win2000 machine, but it fails on Win98 and WinNT4 (and I
guess WinME too but I haven't tested).

Is there any known limitations to Win98 and WinNT4 that would prevent
proper registration of the component?

Thanks a lot.


A.


P.S. All of the above is also applicable for Thunderbird version 0.8
(20040913)