I have a faulty dll and an error address - how do I start analyzing an error?

I have two error logs in the Windows event viewer on our production IIS server:

Source: application error
Category: (100)
Event ID: (1000)
Description: Invalid w3wp.exe application, version 6.0.3790.3959, mscorwks.dll failure module, version 2.0.50727.3603, error address 0x0001da8f.

In a few seconds:

Source: .NET Runtime 2.0 Error message
Category: None
Event ID: 1000
Description: Application error w3wp.exe, version 6.0.3790.3959, stamp 45d6968e, mscorwks.dll failure module, version 2.0.50727.3603, print 4a7cd88e, debug? 0, error address 0x0001da8f.

What can I do with these error messages? I see that I have an error address and a dll name - are there any tools that will show me what is at that address in the dll? Would this be the right approach to finding out what caused the crash? I still could not reproduce it.

Thank.