I dont mean to bump, but its late anyway, and this might prove useful to others:
1 - Antivirus programs are never 100% accurate, so here is an online service which uses many antivirus programs at once to scan your suspicious files. The more antivirus programs in its report that state your file contains a virus, the more likely that's the truth!
2 - I have submitted my jpg files that adaware detected as being infected with a trojan virus, to avira antivirus, for analysis. They might well just be 'false positives' (false alarms) which can happen from time to time. If youre antivirus also warns you, you can sometimes send them to your antivirus manufacturer for analysis. I use avira as my main antivirus, so here is their related page:-
*falls back asleep*