I found 3 figure difference between Gleim and Becker. All these numbers are for 2011. Could anyone tell me which one is correct?

First, Gleim stated that the form 706 (estate tax return) must be filed if the gross estate exceeds $5 millions but Becker stated $1 million.  

Second, Gleim said the applicable credit for lifetime gifts (1,730,800) exempts the first 5 millions of lifetime transfers, however, Bekcer said the applicable credit is 345,800 for the first 1million.

One more difference for the exempt organization. Gleim presented that if the goss receipt less than 25,000, the organization need not to file Form 990, while Becker said the number is 50,000 not 25,000