Boot-time scan and multiboot

So a Full System Scan just found something, and Avast recommended I run a boot-time scan. However, I dual-boot between Windows and Linux. Will there be any problem with the boot-time scan and the Grub boot manager? In my experience Grub is easy to break.

I’m running Windows 7 Professional x64, and using Grub 1 (I think) to dual-boot with OpenSUSE 12.1 x64.

Can anyone answer this before my system is rendered unbootable?

I don’t think it will be any problem on running avast at boot time.
Gurb will be launched before, Windows started (but not finished boot) and avast! will do the job.

Alright, thank you. I’ll let it scan. I didn’t know if the scan touched the MBR or not. I figured not, but better safe than sorry.