Cisco 3750 and 3550 Switches with what appears to be link flapping
 

we are getting the following errors from our Cisco 3750 and 3550 switches. I am wondering if anyone has seen something like this before and knows what we need to do to fix it.

%LINK-3-UPDOWN: Interface GigabitEthernet2/0/13, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/13, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to down
%LINK-3-UPDOWN: Interface FastEthernet0/7, changed state to down
%LINK-3-UPDOWN: Interface FastEthernet0/7, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to up
%LINK-3-UPDOWN: Interface GigabitEthernet2/0/11, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/11, changed state to up
%LINK-3-UPDOWN: Interface GigabitEthernet1/0/18, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/18, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/11, changed state to down
%LINK-3-UPDOWN: Interface GigabitEthernet2/0/11, changed state to down
%LINK-3-UPDOWN: Interface GigabitEthernet2/0/11, changed state to up

Thank in advance for any help you can give me
Steve