Double ARGGGH! So I was just sorting out a test for this in a spreadsheet, and I was horrified to see that there were still some differences once I had built some formulas - which I think just goes to show how tricky it will be for people to work out why the have suddenly gotten whatever number of Nebbers they get :-) Anyway according to my spreadsheet your SQL statement should be as follows :

select cpid,nick,count(*) as mycount from boinc_user
where
metric1 between 995 and 1005
or metric1 between 9950 and 10050
or metric1 between 24875 and 25125
or metric1 between 49750 and 50250
or metric1 between 99500 and 100500

or metric1 between 248750 and 251250
or metric1 between 497500 and 502500
or metric1 between 746250 and 753750
or metric1 between 995000 and 1005000

or metric1 between 2487500 and 2512500
or metric1 between 4975000 and 5025000
or metric1 between 9950000 and 10050000

or metric1 between 24875000 and 25125000
or metric1 between 49750000 and 50250000
or metric1 between 99500000 and 100500000

or metric1 between 248750000 and 251250000
or metric1 between 497500000 and 502500000
or metric1 between 995000000 and 1005000000

or metric1 between 2487500000 and 2512500000
or metric1 between 4975000000 and 5025000000
or metric1 between 9950000000 and 10050000000

or metric1 between 24875000000 and 25125000000
or metric1 between 49750000000 and 50250000000
or metric1 between 99500000000 and 100500000000

or metric1 between 248750000000 and 251250000000
or metric1 between 497500000000 and 502500000000
or metric1 between 995000000000 and 1005000000000

group by cpid order by mycount desc limit 0,25;

I also chucked another band on the end as there are probably some people out there with trillions.
OK I will shut up for a bit now, and stop making blattantly obviuos mustakes (hopfully)