Segmentation fault

Ruby 1.8.7 (2010-01-10 patch level 249)
Rails 2.3.5
mySQl 5.1

I am trying to build a very simple application accessing a single
table in mySQL.
Have updated database.yml. The listing view is ok. But when I am
trying to add a record, I am getting Segmentaion fault at
different .rb file each time.

Can someone please help ?

Thanks