I have created image field on admin. and I got a problem with upload\_dir and base\_url is not same as I set, here's my code:

```
<bankicon translate="label comment">
    <label>Bank Icon</label>
    <comment>Allowed file types: jpeg, gif, png.</comment>
    <frontend_type>Image</frontend_type>
    <backend_model>adminhtml/system_config_backend_image</backend_model>
    <upload_dir config="system/filesystem/media" scope_info="1">theme</upload_dir>
    <base_url type="media" scope_info="1">theme</base_url>                         
    <sort_order>5</sort_order>
    <show_in_default>1</show_in_default>
    <show_in_website>1</show_in_website>
    <show_in_store>0</show_in_store>
</bankicon>

```

When I uploaded 
image save at : media/theme/default
but preview image is broken I check the image link is: media/default ==> theme path is missing.

I have try
theme/default 

still not working.

how can I fix this ? I would like to fix preview image to get media/theme/default

Pls help.