Hi folks, thank you for replying... but i was able to figure it out by myself after going through a lot of trial & error methods. well, i don't know what concept the reader is using but previously i tried adding like 150 pdf files at a time after creating a collection in SD Memory card and it always used to vanish after disconnecting the USB. so, this time i tried adding 15 files only, at one point of connection and bingo!
it worked and i was able to see my collection in reader. thus, i reconnected the reader every time to add 15 files only, using my USB. it was really a time consuming process but this is the only way i could figure out to have all my files in the collection.
my question is.... did anyone try a different method to add more than 50 files at a time to the collection in SD memory card so that they could access it in reader? if so, then plz let me know the way you did and i really appreciate that...
anyways, i am still happy for having all my files in the collection which is now accessible from Reader
... thanks again for suggestions.