[quote user="fwk"]...to make MS work propoerly[/quote]
Note: Properly is how MicroStation behaves now, bucause it "by definition". If you want MicroStation should work differently, it's completely fine, but sometimes configuration or application is required. You should evaluate what is your target: To solve your problem or to use MicroStation without any additional extensions (which makes not too much sence as MicroStation is developed as the extensible platform from the very beginning version).
[quote user="fwk"] i've created a dgnlib...[/quote]
You have to check how MS_GUIDGNLIBLIST is defined and if your dgnlib file is included. Be aware if a new dgnlib file is added into your configuration, usually MicroStation restart is required to the new file be incorporated into configuration.
Because it's a new topic not related to your original question about dialogs, please post it as a separate question for the next time.
With regards,
Jan