I've tried every possible combination of commands to insert a new record
into an Access table, and it just won't happen. Does anyone know if Access
has problems working with .NET?

Check out this link:

http://www.dotnetextreme.com/code/BasicAdo.asp

This is the simplest code sample I've seen anywhere (book or Internet) to
demonstrate how to insert a new record into an Access table (why finding
such an example was like pulling a rhino's teeth is another issue). I
copied the code almost verbatim (mine was VB instead of C#). No dice.

I've made sure my security settings in the folder containing the Access
database are not "read only", etc. Any other ideas, or is ADO.NET a red
herring? I've noticed that a good many other experienced developers are
having difficulty pulling off something this absurdly simple.