OutOfMemoryException while trying to read Access Databse (few hundered MB)

I am trying to read back from an Access database into a Queue(of objects) in VB .Net.

The problem is that the readback works just fine for smaller datasets (say a few MB database). When I try to readback a 200MB into the queue, I start getting a OutOfMemoryException.

The readback is in a background thread of it's own and the dataset has about a 100K rows. At the time, OutOfMemoryException is caught, my queue has a count around 50,000 +/- 5000.

Any ideas on why the system is running out of memory just with a couple hundered MB database(I am working with 8GB RAM)