embedding firebird

I'm try to embed the firebird 1.5.2 server in my asp.net application, the application using Firebird .NET Data Provider 1.7 Beta3, everything works fine but the exception of my collation problem, when i was send the following query to the server, an error returned; something like "arithmetic exception, numeric overflow, or string truncation Implementation of text subtype 55 not located"

//Note: 55 = WIN1254 = ISO-8859-9

the following is the query;
" SELECT * FROM TABLE1 WHERE column1 = 'searchPattern' "

i copied all the files in the distribution (Firebird-1.5.2.4731_embed_win32.zip) file in my "bin" directory, but it didn't work, it's possible the server couldn't locate the required dll ( fbintl.dll ?) but i don't know how can i solve that strange problem?

thanks in advance