What receiver? No problems with the SD #2500 receiver. Did you try a reset?
With the 2500, you can briefly get up to the past 2 hours of listings by selecting a program (info or OK) that started before the current half hour. Then hit LAST to return to the guide. The guide will be at the time for the start of that program, rather than the current time.
Example: If it's 4:15 and you select a program that started at 2:30 then when you return to the guide the guide will be at 2:30. However, you can only move around by line or by page, not by entering the channel #. If you try to move by channel # OR when the current time updates to the next minute (say 4:15 to 4:16) the guide will jump back to the current time. It's more of a glitch that allows you to see previous programs, rather than a feature. Also, I've never been able to go back more than 2 hours.