dropping

when I was using vbseo I was over 20k in indexed pages. On 7/16 I was at 1560 pages indexed and today I am at 904. I didn't have many members posting back in july and we weren't adding articles everyday. Now both are being done but pages are dropping. Sitemap is already setup and links are...

I have a question, since we have switched from Vbseo to DragonBytes I have gone from 20,000 pages indexed to 970. why my indexing is dropping? is this something in the settings? The url structure are the same.