"{$tablename}" is not replaced with "prefix_$tablename"

First issue!

When I use this module, I get an sql error that says it can't find the table. So I thought you didn't use {} to wrap the table name and add the prefix.

Looking at the code, I saw you actually used "{$tablename}", but here this is parsed in php as an escape code to delimit the name of a variable, so that "foo{$bar}baz" is the same as 'foo' . $bar . 'baz'

So replace "{$tablename}" with "\{$tablename\}" or "{{$tablename}}" on line 37 of migrate_i18n_admin.inc, and fix "{$table}" on line 160 of migrate_i18n.module