Elombana - I also have a nextstar and have the same right wing dropping problem. Take a look at this post about my problem. Maybe it will help.

[link=http://www.rcuniverse.com/forum/Aileron_Trim/m_1803835/tm.htm]Aileron Trim[/link]

While I still have not resolved my problem entirely, the advice I received has helped out alot. My problem is not nearly as sever as it used to be.