9780 3G-gprs issue

My BB 9780 keeps going from 3G to gprs service every now and then, and stays there without going back to 3G. I'm from israel and we got almost flawless 3G coverage all over the country so i don't see problems with the reception, the lowest i had on my device its 3 bars inside a building. It doesn't matter if i choose "automatic" or "manual" network selection mode it wont switch back to 3G until i chose manual, scan the networks and choose the 3G band (which is always there and got a great reception). It really bugs me now, do you have solutions for this problem?
Carrier: Orange Israel
OS: .448

I have had this issue for years with the 9780 and the 9000. We have a 3g signal booster in the house so theoretically have full coverage, but it regularly drops down to gprs. To moot it back I have to choose 3g in MObile Options.

I posted about it but never got any help

:(