The best place to ask questions on PIC asembly language would be on the Microchip web forum at http://www.microchip.com/forums/Default.aspx?

This forum is for the MicroengineeringLabs PicBasic Pro & Picbasic compilers.

The primary focus here is helping folks having problems with BASIC, but we do on occasion offer help with assembler.

You should have external pull-up resistors holding your portd inputs high, with each button press grounding an input pin. If you don't have the external pull-ups that would explain erratic behaviour.

Also - be sure on return from any called routine that you're in the proper bank to test portd pins.

I would post all of your code on the Microchip forum for quicker help. It's hard for people to help if they can't see all of your code since the parts you don't show could be where the problem is.