I need some advise:

I have written an application which is used over the Web. I created a DLL
with ISupportErrorInfo for error checking purposes. However, the DLL is
causing the server to crash every once in a while. I am assuming that the
DLL that I wrote is crashing the server, since I haven't had any problems
before. The DLL is used by an ASP page and it's called only once per ASP
page.
(1) What route should I take in order to find the problem.
Again I used ISupportErrorInfo on my dll as follows:
STDMETHODIMP CTest::Out(BSTR lname, BSTR asp_fname)
{
    try
    {
            ...
            ...
    }
    catch
    {
        return Error(" Error Message");
    }

    * Should I return E_FAIL after I return the Error ?

(2) Is it true that if you an application throws an error which is not
catch, it could cause the server to die or crash.

(3) I have also written a VB interface which uses the VC++ DLL that I wrote
and when errors occur inside the dll ISupportErrorInfo propagates the to the
VB Error handler, hence, displaying my Error Messages. Can i do the same
with VBScript on a ASP page.

(4) If my application is not properly releasing memory what route should i
take to solve this problem, I apologize for this question since there are
myriad of answers.

Thanks alot for your time

Jorge