activex componet cant create object

Hi,
i have installed my asp applictaion on IIS 4.0
windows nt is the os..
2>I have using a active dll made in vb and has trnsaction property
"uses transaction"
which installed under MTS.
3>In my asp pages i am calling the com object

The website works fine for most of all the time.
but suddenly when the website is stops working and gives the error
message
active component cant create object.....
it means the dll cant be found.
in iis for the application security is anayomous....
and more strange thing happends if the user opens pcanwhere session to
the web server
and opens the websites form his own pc it works fine ....
how this works

what is tehe problem is realted to
any security...
or some bug in windows nt 4.0
which causing the application to behave strangely.

please advise me how to tacle this problemm
regds,
Navin Mahindroo