Hello Mouthbrooders, welcome to planetcatfish!
What you've seen, two albino parents producing all brown fry, is unusual, but i'm aware of it happening to several other fishkeepers.
Personally I'd guess this is due to the the albino allele originating at two different loci in the two albino parents, since these loci do not match up during mating (and they are homozygous wild type brown at the alternative loci), you end up with a batch of fry wth a genotype that is heterozygous for the albino allele at both loci, and an entirely brown brood due to the dominance of the brown allele over the albino allele at both sites. I hope you understand what I mean, It easier to explain with a diagram and a punnet square really.
Crossing the young should result in a number of albino fry, but the ratios are hard to guess due to the possibility of "crossing-over" (recombination). Also they way the two loci interacact would have to be taken into consideration, but assuming (!)brown is epistaic over the albino homozygous at the other locus, and no recombination takes place, mating two of the young should result in one 16th of the fry being albino and pure breeding with albino siblings for further generations.
Bear in mind however, this two loci theory is entirely out of my head and I have no way of proving it, it just appears to me to be the most obvious answer to what is going on, but there may be something entirely different at work!
Cheers, Conrad
Also, have a look at this thread
http://www.planetcatfish.com/forum/view ... e+genetics