Yes, this seems to be a bug in Eclipse CDT.
As a workaround I suggest you create a custom template which can be accessed with the Ctrl+Space key combination.
In Eclipse Helios: Window -> Preferences -> C/C++ -> Editor -> Templates
Click on New… to create a new template and in the Name field use some descriptive name e.g. “comment-function”, and add your doxygen comment in the Pattern field. Confirm and apply this change.
In your code you can then go to the line above your function declaration, type the first few letters of your custom template name followed by the Ctrl+Space key combination.
In this example:
com<Ctrl+space>
will bring up the Content Assist dialog filtered with “com*” from which you can select the “comment-function” template.
Note:
com<Ctrl+space+space>
will filter even further by only showing Template Proposals in the Content Assist pop-up window.