You should have checked the other posts in the other sub-forum (https://community.sling.com/community/slingplayer_mobile/slingplayer_mobile_for_android). Since you didn't, RafaelB decided to move your post into the Enhancement Request forum. Even though Sling Media has discontinued the Slingbox Classic and has no intention of providing support for it.
RafaelB modified Slingbox Classic
"Hi is there a way of making the new mobile android version work with Slingbox Classic? I have HTC Desire thanks"in SlingPlayer Mobile - 0 bookmarks
There were a couple of other threads where people reported that they Slingplayer Mobile for Andriod application works with the older non-supported Slingboxes. Take a look at the following link, you'll find that there are Android owners whom have posted good results with legacy Slingboxes (https://community.sling.com/message/8652#8652). I assume its the same results that the iPhone users experienced, the app works but Sling just doesn't support it because the hardware is obsolete.
Remember, the Google Market gives you 24 hours to cancel the order before they charge your credit card. So, you're welcome to give it a try.