GPS not always show the logical routing

[coukou]

I've a chinese X-GPS model: GPS-S570HD MTK Win CE 6.0 system and runing iGO8 v8.3.5.193799.
The maps in use are:
Europe 2011.12 TomTom all rights reserved [120102]
Israel 2012.03 GPS and More 2012 [120214]

During my last visite in Israel, my X-GPS not always show the logical routing, it makes me do every time an unneeded detour.
Moreover, it directing me to an opposite way (north instead south direction for instance). As I took the correct direction south, It never recalculate the route and always asked me to make a Uturn.

Anyone have an idea how to fix that?

Regards

[mytheuzen]

May be a map problem.
Check also your settings for road type (unpaved, permit needed..) and route calculation (fast, short, economical, easy).