Group order not accepted for some GMP-ECM factors?
 

I normally upload any factorizations I find using GMP-ECM to factordb. Once in a while it does not want to accept the ECM report and tells me to check the results because the group order does not fit B1/B2.

Does this have anything to do with the Brent-Suyama's extension? And is there anything I should do to make sure the ECM results are accepted?

One easy trick to do is add an extra zero to B2; it will most likely be accepted then.

Factordb itself has a group order calculator ([url]http://www.factordb.com/groupcalc.php[/url]). You can use that to check if that is the issue, and the fudge B2 (and/or B1) accordingly.