throttle plate adjustment

I adjusted my throttle body plate i followed this page http://www.2gnt.com/www/files/tbopen.htm

and then i took it for a test drive and it was AWESOME, it was amazing. Except for one problem, whenever i would let go of the accelerator, and press the clutch in the rpm's would drop slower than normal, and then it would not go below 2250 rpm. It would go back to normal when i come to a complete stop or close to a complete stop. Anyone know what would the problem is?

I put it back the way it was, for now...

OK, i fixed that problem. But now when i adjusted it, another problem came up. The car drives perfectly fine. However, whenever i am coasting with the clutch in or sitting at a light, the rpms will be at 750ish and then sometimes they will randomly go up to 1250ish. It is like it is accelerating it self. SOMEONE HELP ME PLEASE!!! Thanks.