How to prevent plugins from being duplicated?

I had thought this was an “seo meta plugin” duplication problem but it seems that it isn’t…

I have a few plugins and they all seem to be duplicated within the source code… and I am not sure where to look..

any suggestions?

For example… “<!– begin lightbox scripts –>” is at line 90 and 139…

Can anyone point me in the direction as to where I might find the error?

This has probably been a long-term problem but only noticed recently when I tried to add 3-4 of the seo meta plugins but each of them caused duplicate meta titles and descriptions… but it clearly isn’t teh plugins at all…