Alter table on a table with blob

Hi,

I report a great trouble on ALTERing - adding columns - a table with a long binary column:

when I attempt to do it on a about 13 GB database (12.0.1.3867 Sql anywhere on Windows ) using dbeng - with a 6 GB machine -to start it, it crashes

after a short time.

Anybody has info about it ?

Andrea