Ptz And Dvr Ongoing Problems

Now, after many months on and off my little mission of connecting my VCL dome to numerous DVR PC cards. im at the point where I think i have tryed everything.........or have i?

Ive set the protocal of my VC8E to pelco D and so my DVR to the same, via the COM1 port with a RS converter. ive selected the Baud rate ect,

and tryed using the other options on the dvr like

CPELCO_D

CPELCO_P

APELCO_D

TE PELCO_D_D

PECO_D

PELCO_P

all having there own baud rate some 2400,9600 ect

i even downloaded a coms port monitor to check if that works, well i can see the data being transmitted to the prot from the dvr software but nothing happens at the camera?

im guessing its down to the cam????

any ideas as my girlfriend keeps going on at me to throw it, but i cant untill i definatly know it F***ed