I did some searching on google and found out that I have to add the following to the VNCSERVERARGS "-extension RAND" otherwise the geometry setting always seem to be ignored.
For example:
VNCSERVERARGS[1]=" "-extension RANDR -geometry 1024x768 -depth 16"
The other solution is to configure the desktop manager not to use RANDR to resize the desktop from the note I read.
Hope this helps out anybody else that is having a problem with this.
73's
Leland C. Scott KC8LDO