asp.net website randomly hangs after a few hours

Hi,
 I have a site that connects to a access database and asp and aspx pages run in parallel. It works fine for a while then it semms right after the .net portion connects to the database which is does performs its operations like doing a query and updating login info. I then click on the homepage which is a .net page the site hangs.
I need to recycle app pool to fix but whike it is hanging I clicked on a asp page and that works fine only the .net pages are hanging which it does query the database as well with no issues.
I'm using 4.0 framework on IIS 7
one note I use a usercontrol for the header which queries database as well.

please any help on this, really not a complicate site but I'm stuck

Thanks
GI