When I have a standard newform.aspx with a lot of lookup fields the dropdown list appears at the location of the first choice I click.

ex:

1. the first dropdown I click Supplier, appears beneath the field on the correct location
2. the second dropdown I click (Resp), the choices also appear beneath the supplier field.
3. All other dropdowns also appear beneath "Supplier"
4. This is only with complex (+20 items) drop downs, not with the "Unit of measure" field.

Hello,

Here is fix of your issue:

http://sharepointegg.blogspot.in/2010/10/fixing-sharepoint-2010-lookup-drop-down.html

Hope it could help

Thanks, but I don't want to use the simple dropdown boxes.

I need the complex dropdown because they let the users type & filter the choises.

Hello,

I think you should use cascade dropdown to filter values in other DDL.:

http://www.sharepointbinder.com/1/post/2012/09/sharepoint-cascading-filtering-dropdowns-using-jquery.html

>let the users type & filter the choises

If you are looking for solution like: user will enter something in textbox then filter the records then you should try with custom webpart or create custom newform.aspx. Where you can write jquery/ECMA code to filter DDL based on user input.

Hope it helps

I see that chrome renders these dropdownlists fine. IE8, 9 and 10 has problems.

Did you try to run your IE in compatible view? I am not sure what is the exact problem because i am using IE 9 and all work good.

Many people are having same issue and discussion is going on here:

http://jassimkhan.blogspot.in/2010/10/implement-cascading-dropdown-in.html