Problem in 2G ICR to 3G cell reselction

Hi All
We are facing problem in cell reselction from 2G (ICR- network) to 3G (Home PLMN). Even though 3G coverage is very good but MS donot reselect the home 3G network once it get latched to 2G ICR network. Even 3G freq. are defined in the BA list of Donor 2G network.
Following are additional details regarding network:
3G – Huawei System
2G ICR NW – Ericsson – 1800 MHz.
Kindly suggest how to resolve.
Rgds