I have a Slingbox Solo and also a Classic controlling a SA 8300HD TWCable DVR viewing from browsers, iPhone, Mac and PC.
On occasion and with continuing frequency, the on screen remote stops working. The status line under the picture will show multiple commands pending ("2 Pending...") for each and every button "push", sometimes 2 or 3 or more.
In the past with the Classic, rebooting the Slingbox would fix the problem. Currently with the Solo, nothing is resolving the issue.
Physically, nothing is changed and is working properly. It makes no difference which device I'm using for viewing. Also, the software is able to send commands to the Classic controlling an identical box.