I assume you "Patched" the original Tom Tom system/Navcore after you downloaded it from Tom Tom Home using FastActivate or similar! If not that would account for the maps not found or indeed is the map you are installing compatible with the navcore presently installed? Regarding the SD card error. Tom Tom's along with other devices can be a little finicky with different manufactures cards. I found from experience that I only use Transcend class 6 or class 10 cards and have never had a card error issue with Tom Tom's, Garmins or Binatone PDA's so far.
yes i patched the navcore. ive updated dozens of tom toms over past few weeks and never had this problem.
i got the 1GB sd card from ebay for £2 so im guessing this is the problem.
im going to buy a class 6 transcend 2moro and try that.
thanks waldorf will report back once ive tried the new card