If you use a desktop spam filter, then you may be seeing Spam appear in your @SaneLater folder where it used to appear in your Spam folder.
If you are using Outlook:
This is because our computers and internet connection are faster than your Outlook client. That means that we get to your server Inbox before your client does and Spam is by definition usually @SaneLater.
If you are using CloudMark:
You could continue to use SaneBox and Cloudmark, but when you visit your @SaneLater folder, perform this: http://email.about.com/od/cloudmarksafetybartips/qt/et_clean_folder.htm
That will allow Cloudmark to do it's thing on your SaneLater folder.
If you are using Mail.app Junk Mail filter:
You could continue to use SaneBox and Mail.app Junk Mail filter but when you visit your @SaneLater folder do this:
click Messages->Apply Rules or Apple-Option-L
If you use a different desktop spam filter, we can research how to run it's rules on a different folder for you. Please create a Support request.