Instructions for ejecting a CD from a Mac:
1. From within OS X, drag the icon to the trash.
2. From within OS X & with an Apple keyboard, press & hold the "eject" key for at least 2 seconds.
3. Power down the Mac, then power up while holding down the F12 or "eject" key during start-up. Don't let up on the F12 key untill the CD is completely ejected.
4. From within Windows, right-click on the drive and select "eject".
5. Disassemble your Mac so that you can manualy press the "Eject" button in the drive at the appropriate time.
Links:
http://wiki.onmac.net/index.php/HOWTO
http://forums.macrumors.com/archive/index.php/t-254052.html
http://forums.macrumors.com/archive/index.php/t-192164.html
Information on how to install XP SP1 via Boot Camp range from:
1. It cannot be done; you must use/purchase a full install version of XP SP2 not an upgrade version.
2. Make a new bootable install CD by slipstreaming the SP2 stuff into the XP SP1 disk. For example
http://www.winsupersite.com/showcase/windowsxp_sp2_slipstream.asp
3.0 Make a new bootable install CD/DVD that also includes valid Windows 98 or ME install files:
3.1 Copy all of the files from the XP Upgrade disc to a folder e.g. C:\XPCD
3.2 If necessary follow the directions to slipstream SP2 to C:\XPCD\I386
3.3 Copy the \WIN9X and \DRIVERS folders from your Win98 or ME CD to C:\XPCD
3.4 Copy all of the contents of the Macintosh Drivers disc to the a new folder under C:\XPCD (e.g. C:\XPCD\Mac)
3.5 Follow the directions in the slipstreaming guide to burn bootable XP media along with the additional folders we added you may have to use a DVD blank to be sure to have all the files you need.
If you need more information, I'm sure you can Google as well as I. But if not. . .
http://www.google.com/search?num=100&hl=en&safe=off&q="windows+XP"+"how+to+eject"+cd&btnG=Search
http://www.google.com/search?hl=en&q="boot+camp"+"windows+98"&btnG=Google+Search
If you can't get option 2 or 3 to work, then I'm afraid you are stuck with option 1.