USB Flash Drive not recognised

[Admiral]

I am experiencing a really odd problem with USB Flash Drives. They work OK in all other machines running Windows 2000, XP and XP Pro that I can find but on my R50P Thinkpad running Windows XP Pro they do not function correctly. They do not appear in either Explorer or My Computer. They do show up in Disk Management within Computer Management BUT without a drive letter. Yes, I can assign a drive letter there and afterwards can Open or Explore from there but still not from Explorer or My Computer. Yes, they do appear within the Device Manager both under Disk Drives and under USB Controllers with everything within Properties as it should be. In addition, Once I assign a drive letter and Open it from Disk Management I can see the long file names and can copy successfully from the memory stick to the Desktop BUT not the orher way around. From the Desktop or C drive I can only copy short DOS style file names. Otherwise I get the message "destination does not support long file names" HELP!