ASP IIS5 Open Client 12.5 connection difficulty

Why am I unable to connect to ASE (12.5) using a properly configured Open Client (via OLEDB or ODBC) using an ASP page running on IIS5?

On the Win2K server:
* I know the DS is created correctly as I can both ping the ASE server and connect to it via isql.

* I know Open Client is configured correctly since I can set up an OLEDB (2.1) connection, which tests in OLEDB Admin as valid.

* I can also get to the database on the ASE server via MS Access ODBC.

Oddly enough, a stand alone JavaScript using a validated (via UDL) OLEDB connection string works fine, but the equivalent JavaScript on an ASP page fails with the message:
Sybase ASE OLE DB Provider (0x80004005)
[SYBASE][OLE DB Sybase provider][Sybase]ct_connect(): network packet layer: internal net library error: Net-Lib protocol driver call to connect two endpoints failed

Just for reference, the provider in the connection string is:
Sybase.ASEOLEDBProvider.2

I am at a loss to know why a client-based application can connect, but a server-based application cannot.

Any ideas or suggestions appreciated!