Open Nokia Map application, go online whether through through your wireless network if your phone is equipped with or through your ordinary 3G or paid internet connection, downloading of very small amount of Data as about 300 KB is enough to "stamp" your memory card with identification file called QF file then the the solution is simply the following:

If your phone is hacked or you are able to access the following on your memory card:

(Memory Card drive):\private\20001f63\diskcache

copy the file named QF from the above folder and install it on the root of your memory drive.

The excute Map loader (doesn't make difference whether PC suite or Data transfer) it will be identified and then you can download whatever Map you want.

It works for for E71 with V300 software and latest OVI map 3.01.  and not necessary to open OVI map on the phone. just follow steps and open the map loader, will able to detect the phone memory/ sd memory.