Your 2006 Sunseeker by Forest River looks exactly like my 2010 Freelander Dreamer, just different decals. So, with that I'll make a guess that the slideout system is the same. I think this is the manual you are looking for.
Your slideout is "free" to slide in and out if the shear pins that connect the inner and outer drive shaft have been snapped. Refer to this manual (Manual for above floor slide-out system. http://www.eco-rv.com/scripts/pdfretail/get.php?id=365
) It is a difficult, on-your-belly fix but it is possible. You can also replace the shear pins from the cargo hold but in either case you are working almost blind. Having someone else to work with you, one inside, one on the outside makes the job a lot easier.
Also check to make sure the motor bolts are secure/tight. Loose bolts on the motor may lead to broken driveshaft shear pins.