Feeling really dumb right now....after getting an error message multiple times attempting to transfer ebooks from Calibre to my Nook HD+ I finally figured out what the problem was......when you insert a microSD memory card the nook changes the format to something that supports its video files. Hence after transferring a certain amt of books the memory "fills up". When I reformatted my memory card I noticed that the format was some type of "ex file". I dumped it, reformatted it and changed it to a FAT32 card and it has now loaded without any trouble........just something for people to look at and many it will save them the grey hair it cost me....
Thanks for everyones help.....
Pookie