Hello guys (and sorry for my English)! 
I'm working on DotNetNuke 6.0.2 (installed under NetworkService account on Win 7 Ult, VS 2008 Team system, MSSQL 2005 Dev).
I'm developing a module that collects user information and save data to database.
My module has a DnnComBoBox which is hosted by a XmlDatasource control. The XmlDatasource control is bound by an XML file to allow user select a country and an Xslt file to transform the xml file. I built, packed zip, installed the module succesfully.
When I test the module with Admin or Host account (in Edit mode) it works fine, and the data is saved as expected. But when I log out or change the site to View Mode, the ComboBox appears strangely: no nav - down button but a "select" link instead, and nothing happen when i click neither select link or entire the combobox, data is not saved ofcourse. I tried to replace the DnnComBoBox with DropDownList control and the control pop up even with anonymous user, but that was it! No data Submit at all, the site gave me "a critical error has occured..." I created a new portal, then new page and added the module to that page and set the page accessible to every user. I turned back and saw "Permissions" field setting for this module but didn't know what to fill with.
 Did i omit something? Any help would be appriciated, thanks!  

Did you ever figure out what was causing this?   I am seeing this same issue and can't figure out what the cause of it is.

Thanks!

Chaitanya