checksum error

Hi, I've made a yum repository (physp6) using createrepo-0.4.2-1 on a 
FedoraCore2
I face the following problem while trying to get info from a package of 
this repository:

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[root@physp610 ~]# yum info MuPADscilab
Setting up Repos
physp6                    100% |=========================|  951 B    00:00
dag                       100% |=========================| 1.1 kB    00:00
base                      100% |=========================| 1.1 kB    00:00
updates-released          100% |=========================|  951 B    00:00
Reading repository metadata in from local files
primary.xml.gz            100% |=========================| 5.2 kB    00:00
http://physp6www.cicrp.jussieu.fr/yum_physp6_repository/fc3/repodata/primary.xml.gz: 
[Errno -1] Metadata file does not match checksum

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Has anybody faced this problem and know how to solve it?

thanks

Ivan