TString problem

Dear Rooters,
  I have a problem with TString, the command worked before with the following lines when I tried to make a new string with part of long string s2=s(a, b), but now the same lines did not work anymore, did somebody know what is the problem and how could I solve it? Thanks very much for your help!
  Best regards,
Yaxian

pb-d-128-141-48-247:corr ymao$ root -l
##]root [0TString run ;
root [1] TString fileArray[6000] ;
root [2]
fileArray[0]="alien:///alice/data/2010/LHC10d/000126432/ESDs/pass2/AOD018/0099/AliAOD.root"
(class

TString)"alien:///alice/data/2010/LHC10d/000126432/ESDs/pass2/AOD018/0099/AliAOD.root" root [3] fileArray[0].First("AOD")
(const Ssiz_t)44

root [4] fileArray[0](44,6)
Error: Can not access pointer to function 0x1018a7808 from interpreter(2) FILE:(tmpfile) LINE:1
root [5]

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.