I'm using 3.2.2.BETA4.
My prior selenium tests manipulated the fileUpload component ok, using the following:
<tr>
<td>type</td>
<td>attachments_addFileForm:attachments_fileupload:file</td>
<td>javascript{test_file_upload}</td>
</tr>
<tr>
<td>click</td>
<td>//a[contains(text(),'Begin upload...')]</td>
<td></td>
</tr>
<tr>
<td>click</td>
<td>attachments_CloseLink</td>
<td></td>
</tr>
<tr>
<td>waitForElementPresent</td>
<td>referral:referralAttachmentTable:0:attachmentType</td>
<td></td>
</tr>