This problem happens if you use the same column name in 2 tables.
I always recommend using unique column names in each table.
The naming convention i like to use for naming columns is to prefix the table name to the column name
where you are working with a version and language table, and example would be:
versions:
versionID - primary key
versionCompond
versionDescription
versionLanguageID - relates to languages.languageID
etc....
languages:
languageID - primary key
languageName
etc....
Using this naming convention prevents the ambiguous name error and prevents confusion since you can more readily identify the table a column name refers to by it's name.
to fix the probelm in your current pages, edit this code:
$WADbSearch1->addComparisonFromEdit("language_id","language_id","AND","=",1);
to:
$WADbSearch1->addComparisonFromEdit("tbllanguage.language_id","language_id","AND","=",1);
the page you sent only deletes from the tblversion table, not the language table, i suspect the problem on your other page is related to the Key Column you selected.