In my application developen in oracle forms 6i and migrated to 11g icons are loaded from a jar file, it's working fine, icons are showed without problems.
i have already read the chapter 4.9 Deploying Icons and Images Used by Forms Services in B14032-03.
Icons are showed by Set_Custom_Property( 'QMS$TOOLBAR.QUERY', 1, 'SET_IMAGE', '/query.png,CM' ) using LAF classes.
In most cases, problems with displaying icons is the result of an incorrect path or filename typo. The easiest way to find these types of errors is to look at the server side logs and client side java console. If you look closely at the request for a particular failing image/icon likely you will find that either the URL to the file is incorrect or the actual file name is incorrect.
I have reviewed all logs but i haven't found any reference to any icon.
The icons aren't loading from web tier, they are inside a jar file located in classpath forms/java, the forms applet received this files as params
<applet mayscript="" name="my_app_applet" archive="frmall.jar,rolloverbutton.jar,my_app_icons.jar,FormsGraph.jar,jacob.jar,frmwebutil.jar,csutil.jar,ehb.jar,JDICplus.jar,jazzy-SpellChecker.jar,JSpelling.jar,dvt-jclient.jar,dvt-utils.jar,jewt4.jar,xmlparserv2.jar,frmwebutil.jar,jacob.jar" code="oracle.forms.engine.Main" codebase="/forms/java">
Even when the icons come from a jar you will see a request for it in the console. For example, I have a jar named "oracleicons.jar". When an icon is loaded (or attempted to be loaded) from this jar you will see a client console entry that looks something like this:
<blockquote>basic: Loaded image: jar:http://myserver:8890/forms/java/oracleicons.jar!/images/copy.gif</blockquote>
Be aware that the exclamation point after the file name is expected. It may be necessary to enable trace level 2 or full console tracing to see these entries.
So. in my case, the jar has a subdirectory "images" and the image my form requested is "copy.gif". Notice how that is shown in the above console entry. In your case, look very closely at the complete entry. Take note of the complete path and file name. Also consider case sensitivity. Your form and the file name in should be of the same case. In other words, copy.gif is not the same as copy.GIF or Copy.gif.
After review the problem, i think that i found the solution.
In when-new-form-instance we have a call to set_custom_property(...,'SET_IMAGE...'); that in item with LAF implementation class show that image in buttons.
When the forms are called from another form within the application the images are shown without problems.