We have a "new" 2006 25' Safari too!
And our slide out bed extension thing was difficult to pull out and the door under it had to be open to do it. Hubby was trying to get it out and the trim/handle came off! While trying to put it back on we discovered the drawer slide system was held on with only 4 screws, 2 of which had come out!
The only way he found to get the slide out was pull it out as far as possible, and there was screw on each side he removed, which let the slide come all the way out. He then filled the wallowed out holes (with match sticks and glue and wood putty) and put screws in EVERY hole he found. I think it was 4 on each side. It's nice and solid now and slides in & out nicely.
I think we need to put 2 or even 3 legs on there so when it's out it's supported. There is room to swing them up, but not sure how we'd keep them up. Haven't worried about that, since we may not use it and it's so much sturdier now.
All that said, I'm betting you have 1 or 2 (or more!) screws in the track preventing it from being pulled out. Maybe get all the stuff in the space underneath out and pull from the back or see if you can find the offending screws.