What do this boot errors mean?
 

vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
unknown: <PNP0303> can't assign resources (port)
unknown: <PNP0501> can't assign resources (port)
unknown: <PNP0700> can't assign resources (port)
unknown: <PNP0401> can't assign resources (port)
unknown: <PNP0501> can't assign resources (port)
Timecounter "TSC" frequency 2004557470 Hz quality 800
Timecounters tick every 10.000 msec
GEOM: create disk ad0 dp=0xc31d2560
ad0: 78167MB <Maxtor 6Y080P0> [158816/16/63] at ata0-master UDMA133
acd0: CDRW <HL-DT-ST GCE-8525B> at ata1-master PIO4
acd1: DVDROM <PCDV5016G> at ata1-slave PIO4
Mounting root from ufs:/dev/ad0s2a
NVRM: detected agp.ko, aborting NVIDIA AGP setup!
NVRM: detected agp.ko, aborting NVIDIA AGP setup!
Warning: pid 585 used static ldt allocation.
See the i386_set_ldt man page for more info
NVRM: detected agp.ko, aborting NVIDIA AGP setup!
NVRM: detected agp.ko, aborting NVIDIA AGP setup!



I wonder what goes wrong .. if have probs with my 3d acceleration, its terribly slow

The problem is you screwed up your install of the nvidia drivers. You compiled the nvidia drivers to use the nvidia agp driver and left the freebsd agp driver in the kernel.

If your running 5.2.1 then you can edit /boot/device.hints and add hint.agp.0.disabled="1". Reboot then in your /etc/X11/XF86Config set your agp drivers to the nvidia ones by using Option "NvAGP" "1"