Kernel panics- how many is too many?

Question

I use my MBP as my primary computer. It is on approx 12-14 hours a day. I am a heavy Photoshop, Illustrator, Aperture, VMWare user and use some more scientific software in addition to Office Word and Excel. I work in 2 locations and my MBP sleeps with the lid closed when I travel. I shut down every night.
Of late, I have been experiencing 2 kernel panics a week. As a recent OS X convert, I was wondering if this is normal behavior?

Answer 1

Thank you for your responses.
The panic.log from the console doesn't really give much useful information (at least to me). The 'Backtrace' fields, which I assume trace back system events till the panic are different for the different panic events. I am including the relevant lines:
Tue Oct 16 00:47:02 2007
panic(cpu 0 caller 0x0035E7BD): mbuf address out of range 0xffffffff
# yadda yadda yadda
Sat Oct 13 11:16:35 2007
panic(cpu 1 caller 0x001A4A55): Unresolved kernel trap (CPU 1, Type 14=page fault)
#yadda yadda yadda
Kernel loadable modules in backtrace (with dependencies):
com.apple.nvidia.nv50hal(5.0.6)@0xc29000
dependency: com.apple.iokit.IOPCIFamily(2.2)@0x664000
dependency: com.apple.NVDAResman(5.0.6)@0x782000
com.apple.NVDAResman(5.0.6)@0x782000
dependency: com.apple.iokit.IOPCIFamily(2.2)@0x664000
dependency: com.apple.iokit.IOGraphicsFamily(1.4.7)@0x758000
dependency: com.apple.iokit.IONDRVSupport(1.4.7)@0x773000
Mon Oct 8 07:40:32 2007
panic(cpu 0 caller 0x001A4A55): Unresolved kernel trap (CPU 0, Type 14=page fault)
#yadda yadda yadda
Kernel loadable modules in backtrace (with dependencies):
com.apple.filesystems.smbfs(1.3.7)@0x3d46b000
It seems that the panics have been caused by Nvidia drivers and Samba filesystem. A previous panic was caused by the airport card.
I appreciate your thoughts on this issue. I will give disk util a chance to repair what it can. I am planning to install Leopard anyway, so will keep it as ut is till the Leopard update.
Thanks
BL