I'm currently using SQLyog v 9.61 Ultimate and I think I'm encountering a small bug, though it's fairly easy to work around in the meantime.
When I have completed defining a new table, using the tabbed interface, I get a syntax error (1064) when pressing the Save button. I've done a bit of investigation and it appears that there is a bug when you define a default column value and provide a comment for the colum. In this scenario it doesn't appear to put a space character between the default value and comment in the generated SQL – thus causing the syntax error. I've tried various field types and all are effected, so I suspect it's a global problem.
E.g. a simple table I'm getting the following in SQL preview.
Create table `NewTableTest`
`id` int UNSIGNED NOT NULL AUTO_INCREMENT,
`testIntField` int DEFAULT 0COMMENT 'comment int test',
`testVarcharField` varchar(25) DEFAULT 'default val'COMMENT 'comment varchar test',
`testCharField` char(25) DEFAULT 'default val'COMMENT 'comment char test',
primary key (`id`)
);
It it easy to work around this by copying the SQL query from the preview tab, and manually adding the spaces where necessary.