LuckyLady, I'm very sorry but I think you're stuck. Any time you have 99+ of a specific creature item in your inventory, the game will crash when you go to turn it in and Bioware, in an early patch, 'fixed' it so you can't sell or destroy creature research items now. Your only options, as I see them, are to either go back to the 'pre-brains' save, or avoid turning in research for the rest of the game.
I might also suggest that using F4 is a safer way to accumulate materials (crafting and quest), since selling them, with F4 turned on, to vendors increases your stock of any such material by 99, but since creature research isn't on the 'sale' list, it's unaffected. Crafting/Requisitioning with F4 turned on, also does not deplete your stock of materials (and will boost them to the next interval of 99). But you do have to have F4 turned off when turning in creature items to the research table since when turning in any item, an active F4 will add 99 more to your stock, which will also be also turned in and crash the game...