Do you have photoshop at home... It can open tga... And convert other formats in tga... And if u want to convert from tga to blp go download image extractor...
wc3viewer is pretty much the best converter IMO. it allows you to convert tga, jpg, bmp, all to BLP and BLP -> tga, jpg, bmp. you aren't going to find a program to actually open a BLP because its proprietary to blizzard only.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.