Site Punished for Having a Large Number of Links From One Site?

How many is too many?

[fraserwebguy]

Thanks for reading my post first.

About 2 month ago, I decided to try to create about 50k text link-ins from one of my website(B) to another important one(A). And from this month, I find my A site's homepage pr get lower, but B site is still the same! And many pages in A get much lower serp. B site is a real site with a lot of pages / content, and PR of the pages is from 0-4.

Is that possible the PR losing caused by the large qty of text link-in? how many text link-in from another site (per site) is acceptable for google?

Thanks.