[c-nsp] Simultaneous drops - 2 upstream providers

[CiscoNSP List]

Hi - bit of a strange one - We have 3 interpop links (3 different carriers) terminating on a 3750X+ASR at one of our POPs, and are seeing intermittent drops on 2 of the links(And ospf loses adjancency) at the same time 
Carrier A - POPA -> POPB - We see drops/ospf adjancency issues once/twice a dayCarrier B - POPA -> POPC - We see drops/ospf adjancency issues once/twice a dayCarrier C - POPA -> POPB - No issues at all
All links terminate on the same 3750, and then are trunked to an ASR1006 for L3 - There are no errors/physical link issues on the 3750, and both carriers also do not see any errors/link drops.
It would be improbable that both carriers have issues on there networks at precisely the same time, so it is either our switch(3750), or something weird happening with the x-connects that doesnt cause the links to drop, doesnt cause any errors etc, but causes ospf to lose adjacency (but only for 2 providers, not the third?)
Any suggestions/assistance is greatly appreciated