Thanks Marvin!Now that we've established that, we'll just have to stick to the copper.

Leo,I'm running into something similar.We just put in new 4451 routers with GLC-SX-MM Part # 30-1301-03 (SFP's)and we're trying to connect to a new 4507R+E 10gig Module using SFP-10G-SR Part#10-2415-03.When we plug in the new cable we get no link lig...