I have three OS's installed on my hard drive (Fedora, OpenSUSE, and Ubuntu) and I think that they are sharing the one swap partition. Here's my drive according to fdisk:
When I first boot to Fedora, before X starts it says for a few seconds:

The SDA3 partition says "Linux swap/Solaris" because I previously tried to install Solaris but aborted the setup. Could this be a problem? How can I tell for sure that Fedora is using the swap partition? Thanks in advance.

The reason it says "Linux swap/Solaris" is because Linux swap and Solaris share the same partition ID. That's perfectly normal. Check the output of 'free' in the swap line to see if it's recognized. I suspect the error message is more related to something confused about power management.

It's not a problem if you have lots of RAM and don't even use the swap as my system doesn't. From the output of free...
Kind of an annoying message at any rate.
It's likely that your Fedora /etc/fstab points to a swap partition label which got borked during one of your install attempts.
I would just relabel it like this...

You should have "system monitor" on FC6 it's in System > Administration. Under resources it will say how big the swap partition is and how much is being used.
I had a similar error using multiple swap partitions, but all of them were mounted.

How would I do that? I tried "free /dev/sda3" and that didn't work.

System Monitor says that 0 bytes of my swap partition was being used...is that normal? Does the swap partition only get used when RAM is completely full?

By the way, do you know how to launch System Monitor in KDE? I couldn't find it. Thanks.

'man free' - free doesn't take a device argument - just 'free' should return something like
If the swap/total said '0' instead of '979956' or some positive integer, then your swap would not be enabled. The 'used' part is irrelevant to whether it *can* be used.

Generally, as you see with mine, after a while, a dribble may be used even if physical memory is not completely used. But, initially, seeing zero in use is not uncommon. So I wouldn't worry about it either way. If it needs to be used, it will be, so long as a proper swap partition exists, and swapon(8) has been done and so on.

Huh - R'ing TFM (of swapon) myself, 'swapon -s' should serve as well as eyeballing the output of free. Either way, though.

Quite true, but I prefer using the command with the -m (output in MB) and -t (lists the sum of RAM + swap) arguments. It's more readable:

To revert to you first question, you're seeing the message because the newer FC kernels check the swap partition to see if there''s a "suspend" image stored on it, and then to resume from it if one is found.

I'm not sure (since I seldom suspend), but there may be a "suspended" flag set (probably as an empty file in /) which triggers the "check for suspend" actions.

In any case, it's harmless. Unless, of course, you're actually trying to resume.

As to the other part of your question, many (but not, I think, all) distributions will automatically mount all the swap partitions they find on your system, and use them as necessary. So, if you actually suspend a FC session, then boot another distribution, the other distribution might overwrite your FC suspend/resume information so you'd not be able to resume.

If that's the case, make it an alias rather than specifying the options every time.

PTrenholme - now that you describe fedora's suspend mechanism, that sounds exactly right - except there's little 'might' about it. Swap is assumed to be scratch space and another distro would use it as soon as needed, so only sheer luck or no swapping would avoid the overwrite, I suspect. I wonder if this is common? Seems like a /.suspend file or /var/tmp/suspend (or something) should be created rather than using swap. Though, granted, that would require unallocated 'real' filesystem space. I dunno, though - I never use such features.

Go2doug
To check if Fedora resumed swap in KDE, open System/KInfoCenter and click on "memory". If the swap section is not light green, then it was not resumed. I have had this happen in a couple distributions, Mandriva and Fedora. For Mandriva it was a result of changing the position of the swap partition in my boot manager from the 3rd partition to the 2nd partition after getting rid of the /home partition and moving it up the list. Even making the appropriate changes in /etc/fstab did not get it to resume, I had to put it back in the 3rd partition position and leave the second empty. I have an elaborate boot manager that only let's the OS see the partitions I want/it needs to see, so this may not apply to your case.
For Fedora, I have the x86_64 distribution, when I installed ntfs-3g from repositories and left SELinux in enabled mode, most adminstration and system setting features were not accessible, thus I could not even turn off SELinux. When I tried installing ntfs-3g from repositories on an image of the FC 6 installation with SELinux in permissive mode, the kernel could not resume swap, but everything else worked. I had to manually mount with command: 'swapon'. To remedy this I had to wipe that one out and load another image and install ntfs-3g and Fuse from source, everything works not using them from repositories, even after countless kernel upgrades since.

Yuck.

Check for a "resume" keywork in your loader parms - you can always change it to noresume.
There's always suspend2 as a (better ???) option as well.

Personally, I prefer a distro where *I* make my own choices as to what gets installed/implemented.