Coolant Reservior Leak

[VBdenny]

I noticed while looking at my engine tonight that there appears to be a leak around the top of my coolant reservior. I just had the system flushed last year and the car never runs hot. The level is only slightly below the indicator marks, yet now everytime I look I seewhere coolant has been seeping.

In addition to the cap, there is the other cap which connects the low fluid indicator but I can see where it is leaking from. Does the seal on the tank ever go bad? That's sure what it looks like to me.