I have tried for months to research this problem and had almost given up.
Basically I had a fully functional sat nav 400i and I wanted the latest maps. popped along to Naviextras and they said I had to install their update software. Since then the system loads and says:
"Updating navigation system please wait.
Then beneath that notice it says:
"deleting DATA.ZIP"
and the head unit sits there and does nothing else. I contacted Naviextras and they gave me the run around for the last 6 months and I've almost given up on this.

I have the original card and a cop and they both have the same effect.
Is there anyway to clear this from the system?

I think this came up before and turned out to be corruption on the internal drive, I can't remember what the outcome was.

I will try and find the thread.

BTW Navsure devices use a special version of iGO to control the hardware sounds mixer, cracked versions available from here, and other sites lack this feature, so you will get no sound.

EDIT: This is the main discussion thread...
http://www.navitotal.com/showthread.php?12467-Navsure-Original-SD-Card
There are others too...

Thanks FBF good reading.
It seems like the head unit is stuck doing an update. It might be the case that I have to bin it and get a new one perhaps.

Unfortunately not every device can be modded, and Navsure is one of them.

No worries. It was a nice unit when it worked. That said I have tried out my shiny new Binatone F430 with the instructions for Primo2 and boy this is a fast animal now. Also accurate and can work out if the destination is close behind you rather than sending you in loop for miles only to come back to the same place.
So the money I loose binning the Navsure n400i I'll make up with the Binatone F430.
I just have to find something to fill that huge whole in the dashboard now