I was punished for using google sitemaps!!!!

Yes what i said in the title is actually true!
On one of my sites ,I found that the google sitemap was showing errors in my google webmaster central.The error was that I had not set the priority of my site pages in the xml sitemap properly.So what I did was set some default priority to my pages in the xml sitemap.
the next day to my surprise I found that all my serps had gone beyond 50.Previously they were in the first or second pages but suddenly it went down.I had done no other seo change to my site.
Also I would like to furnish the following data in favour of this penalty:
Two weeks ago my site had got a pr update and an increase in the pagerank.Then after the pr increase I was able to find that my serps had improved.But after I changed the sitemap my serps suddenly fell down.So I strongly believe that google punished me for setting the priority value in my sitemap since there's no other visible reason!I think that google thought I was trying to fool google by telling them that some of my website pages were more important than others.
Now i have nothing to do other than wait for about atleast 1-2 months
pity me ;-(

 

omg this is what I see for one of MY SITES!! changing it right away! thanks for the heads up

 

yeah , But I never set priority..

 

I have all the pages in my google sitemap set to "<priority>0.5</priority>". Should I change it or should I just remove it completely. Is not having a priority set bad or is setting a default priority worse?

EDIT: I also have "<changefreq>weekly</changefreq>" which probably isn't true. Should I remove/change that also?

 

ho last week only i have submitted my sitemap to google webmaster tools.........

 

I am telling not to change anything for now
I am not telling that sitemaps is bad,but what I am telling is that sitemap can be deadly for new sites without much authority as google thinks that we are trying to fool google by telling them that some of our pages are more important than others with the priority tag!
This dosent happen with old sites!
And plz dont change anything in your sitemap as it may trigger more penalty from google,rather just wait till everything returns fine within aa couple of months

 

I dont submit site maps. Done that years back and didnt get any noticable differnce. From there on, no sitemap for me and no headaches!