I upgraded a machine from 0.90.1 to 0.90.2 and seems there is a problem with duplicate signatures, I now see over 200K viruses:

----------- SCAN SUMMARY -----------
Known viruses: 200101
Engine version: 0.90.2
Scanned directories: 2
Scanned files: 18
Skipped non-executable files: 0
Infected files: 0

Data scanned: 1.68 MB
--------------------------------------
Cancelled
--------------------------------------

Looking in my db directory I see:
15/05/2007 10.28 457.898 daily.cvd
08/03/2007 12.21 8.189.490 main.cvd
15/05/2007 11.30 <DIR> main.inc
15/05/2007 11.28 104 mirrors.dat
3 File 8.647.492 byte
3 Directory 32.285.933.568 byte disponibili

Clamwin should make sure only one version exist of main.*/daily.*, deleting the duplicate during db update, and not loading both during scans.

empty the db folder and redownload it

I already fixed it by simply deleting main.cvd.

But it would be nice if this get fixed by the program, other can have the same problem, and maybe they does not know it.

normally freshclam would delete main.cvd when it unpacks it. Something must have gone wrong with your setup