Failed to read header + session not found

Hello!
I have a TChain, where I Add different TFile.
During the adding of all this file i get several messages like that:
130321 10:11:38 001 Xrd: GoToAnotherServer: Going to: lxfsrk52c02.cern.ch:1095

why?

Then I start a simple Loop on all this events (~10^11).
And what I get is a lot of messages like that:
130321 10:16:31 001 Xrd: GoToAnotherServer: Going to: lxfsrk45a02.cern.ch:1095
130321 10:17:08 9447 Xrd: XrdClientMessage::ReadRaw: Failed to read header (8 bytes).
130321 10:18:58 001 Xrd: GoToAnotherServer: Going to: lxfsre46c03.cern.ch:1095
130321 10:18:58 001 Xrd: CheckErrorStatus: Server [lxbrf39c03.cern.ch:1094] declared: session not found(error code: 3011)
130321 10:19:38 9447 Xrd: XrdClientMessage::ReadRaw: Failed to read header (8 bytes).

Is the number of my events too big? This macro usually works for few envents!

Best,
Luca

P.s. please find attached my macro
FillMassPlot.C (3.85 KB)