problem with yum

Hi Actually it will be wrong to say that Its a problem with yum. I ran "yum update" . Everthing was going well until I accidently pressed Ctl-c when yum was cleaning up old packages( Last step when yum updates). Now when I view the installed packages by doing "yum -qa | sort" I see multiple versions of the same package. I looked at yum manpage, but no help. Can I do that cleanup process manually. may be I can try manually erasing the old rpm packages. But I am not sure whether the two versions share some binary files or not. If they share binary files, then this option gets ruled out as it will erase usefull files. I dont know what yum does internally. I have tried rebuilding the rpm database and yum clean all. But no help. Can I let the system remain as it is? Are the multiple packages only entries in yum database or I am having two version of the same software (seems unlikely)? Wont it create any problem? I dont care if these packages are taking a little space as long as they dont create any problem to system functionality. Thanks In advance. -- pritam