Google sitemap problem

Hi
I made sitemaps for a site one month ago. The sitemaps are ok(no errors) but the results are very bad.
At the begining I had:
1000 articles and 3400 forum pages indexed.
3 weeks, after I submited sitemaps I had:
11000 articles and 9800 forum pages indexed.
4 weeks, after I submited sitemaps I have:
4000 articles indexed and 800 forum pages indexed.

It is strange that number of visitors was the same during this month. But I'm afraid to estimate how many pages will I have indexed after another week. I might lose my job. What the hell is wrong? Plese help me.

 

I've seen the same:

week 0: 25k pages
week 1: 10k pages
week 2: 25k pages
week 3: 200k pages (??? dunno why)
week 4: 25k pages
week 5: 10k pages (that's this week)

So I think it just fluctuates a lot more when using a sitemap compared to not submitting a sitemap. Traffic has gone up (a bit) since week 3 -- and stayed about the same in week 4 and 5, and well, that's what important right?

 

is there a pattern as to which pages are being discarded? I know a lot of forum urls are fluff...search, user, login, post etc. I deleted those from one site map with phpbb I submitted and left them in another.

 

I don't think google dropping pages has anything to do with sitemaps. It is likely they are dropping them for other reasons. Being in a sitemap doesn't guarantee google will keep your page indexed. It is just a tool to make sure google is able to get to all your pages and knows about them.

The same criteria is still applied as to whether a page is kept in the index if it is in a sitemap or not.