If it was me I would upgrade from 8.0.5. 8.0.5 in addition to being unsupported is also a strange mixture of 7.3.4 and 8i features. Unless of course you don't want to pay for support. which is a whole other situation.

If nothing else you can recreate your standby. Before you recreate the standby you can activate the standby and verify that you have a valid stand by.