I tried this, and get the exact same errors on both login, and forgot password pages.
After walking through the generated code, and include files, I figured out how to echo back the generated query, and realized there were no quotes around the username and password field data in the query. This appears to be due to incorrect column types (blank column types) being passed to the WA_GetSQLValueString function as the query is being generated.
I looked through the generated code on my login page, and see that the column type is blank
"columnTypes" => explode($WA_Auth_Separator,"".$WA_Auth_Separator.""),
"columnTypes" => explode($WA_Auth_Separator,"text".$WA_Auth_Separator."text"),
and on the forgot password page,
"columnType" => "",
"columnType" => "text",
Since this bug makes the login function and forgot password function unusable, I assume that this happens only under certain circumstances.
I am running Dreamweaver CS5.5 on Windows XP pro.
Hopefully that will help them track it down.