Sudden drop in CPC after placing my own ad codes.

Hi everyone,
I have a question about CPC dropping, I recently purchased a site which had a stable $0.50 CPC, but after I placed my own ad codes(replacing seller's codes) on same Spots with same Ad format, the CPC is now around $0.10(from the last 5 days)
so my Question is,
Is it Strange or normal after getting hands on a new site?
Will it get back to the old CPC that it had a few days back or its permanent now?
Keep in mind My Adsense account is Fresh, I created it this week.
regards
Xalmey

See original post by Xalmey