Help me, A memory Card problem

I have a Samsung E200 mobile phone. I inserted a Micro SD memory card to this phone & it's working well, but the problem is that I can't download the files received by Blutooth from the memory card to pc, at the same I can download ONLY the files preiousely added to the memory card from any pc. The following error message appear: "Can't copy file:............, Access is denied, the disk may be full or write protected". This problem occurs on all versions of windows XP, while it's absent with windows Mellineum. I want to say that I don't lock the reader lock button, Also I used the program named "Unlocker" and it find that my files are not locked or used by any other program..