With reports continuing to circulate that Dallas-based Blockbuster plans to file for bankruptcy before the end of the month, the home-video renter announced Monday that its CFO, Thomas Casey, had resigned after entering into an amended employment agreement last week that included an increased severance payment. Home Media magazine quoted a source as saying, "They pushed him out and gave him a departing gift with the bonus." (The Dallas Observer , citing a Sept. 7 "separation agreement," said that Casey received a lump-sum bonus of just $100,000 and $7,000 in relocation expenses.)