alter table return error

[Philippe Poelvoorde]

Hi,

I'm trying to add an 'unsigned' attribute to one column :

 > alter table markets modify Id integer unsigned not null auto_increment;
ERROR 1025: Error on rename of './eurex_dax/#sql-1d2c_2f' to 
'./eurex_dax/markets' (errno: 150)

The query runs without any problems on any others tables (all are 
innoDB), all permissions seems to be fine. I don't really know where to 
look for hints, any ideas ?

-- 
Philippe Poelvoorde
COS Trading Ltd.