[web2py] Slow queries or how to determine if cache is working?

[pbreit]

I'm struggling to figure out if caching is working. I insert a list of 
categories on pages where I show a bunch of items for sale. First, I only 
have 400 items in the DB and it takes quite a bit longer than I would 
expect to display the first time. Second, I am trying to cache the query 
and it doesn't appear to speed up at all. Does this mean my problem might 
be elsewhere? Is there any way to tell that caching is working?

Here is my page:
http://pricetack.com/items

The component (I've tried cache.disk as well):

def item_groupings():
    seller = db(db.auth_user.name==request.vars.seller).select().first()
    if seller:
        groupings = db((db.item.status=='active') &
            (db.item.seller==seller) &
            (db.item.grouping!='test')).select(db.item.grouping,
                orderby=db.item.grouping, distinct=True)
    else:
        groupings = db((db.item.status=='active') &
            (db.item.grouping!='test')).select(db.item.grouping,
                orderby=db.item.grouping, distinct=True, cache=(cache.ram, 
360))
    return dict(groupings=groupings)

Maybe I should try to generate the HTML in the controller?