I'd try some longer-termed, more vigilant basal testing. Such problems are almost always basal related. Make sure you do not eat anything for at least six hours before your test period. Yes, I said six (6). Humalog lasts about 6.5 hours, and you need to eliminate all bolus effects as well as food, exercise, stress, etc. Test at least every hour, and test twice to confirm the values. Test more if off. Try staying up all night if you can, say a Friday night. Eat a 5pm or 6pm dinner, then test every hour or better starting at midnight. Go as long as you can. Go nuts, rule out basals with authority!
My next suspect is inapproriate boluses. I know many try to get that 2hr peak down to under 6, but that plan can create hypos later. If you eat carby foods, you need to live with the spikes. Sorry.
There's anotehr possible mismatch you might need to investigate, but I'd like to see your basal patterns first. If your patterns are roller-coastery, like mine are, bolusing during a peak can result in a basal when your metabolism troughs, and the converse is true too. My 8 AM I:C is 1:4 or 1 unit for every 4gm of carbs. My 10am to dinner I:C is 1:10. Remember I said Humalog lasts 6.5 hours (ignore your pump setting, that's different). My 8 AM bolus is fine for my 8 AM needs, but the lingering isnulin then becomes too much from 10 AM to roughly 2:30 PM -- I inadvertently overdose on insulin. I get around this by not eating until 10 AM or superbolusing - running a reduced temp basal during my OD periods. Make sense?
Also, take a look at this page. It may help you sort things. http://www.diabetesnet.com/about-diabet ... lin-action