This has happened more times than I care to count!
As has been said, the stock of blue rams seems to be horrible! Many of them have internal parasites when you buy them... I have had better luck taking them home and treating them like I knew they had something wrong with antibotics and such. Seemed to make them last antoher month or so, but they died off as well in pretty short order. They do like a nice clean tank with very soft, warm water and acidic ph. My longest lasting fish were in a tank that I treated with peat, kept about 80*F, and ph around 6.5. I've heard they like the ph quite a bit lower to around 6.0 or even into the high 5's... this is supposed to help ward off some of the nasties they are suseptible to.
Anyway, wish me luck also!... I just picked up 2 more pairs (I think!) at a fish auction last weekend that are supposedly wild caught. One pair seems to have paired up and getting along ok... the other pair still has the male aggressively chasing the female whenever she comes out of hiding. hope he doesn't kill her soon!! Both pairs are in 20 gallon planted tanks. One I have some peat in the filter, but have not check params yet... hopefully will get some eggs soon.
Best of luck,