[linux-audio-user] demudi install confusion

[Greg]

hello list, 
I've been lurking since I decided to install demudi on my xp system. 
So far I've cooked my XP install twice in the process...  I've checked
FAQs and other guides and no luck yet. Here's what I'm doing.
demudi 1.2.0 iso, using the default installer
I run  linux26 dmraid (SATA drive)
partitioning:
15gb XP ntfs
2.5gb linux swap (aside: is this too big or should i go by the 1.5x
rule and do 3?  I have 2 gigs of ram)
4gb "  /  " partition
150gb "/home" partition
everything but the xp partition is a "logical" partition.
Now, I want to be able to keep XP's MBR intact.  The first install i
totally goofed.  The next time I tried to get it to install GRUB to a
floppy, I couldn't figure out if I should use /dev/fd1 or /floppy or
what and it just hung.  Now I've read that once everything's groovy
it's not too complicated to make a linux boot instruction to add in
xp's boot.ini, but I need to get this up in the first place.
So...
1. are these good partition sizes?
2. is there a good install guide that talks about using the default installer?
3. is there a better way to install demudi / how can I do what I'm trying to do?
thanks hope this is list-appropriate etc.