I've found that moving my page file off of my boot drive and making the page file minimum and maximum sizes equal to about 1.5 times the amount of physical RAM on my system seems to smooth out the glitches when I'm playing games.
Increasing the refresh rate will reduce flickering, but that's not the same as the short pauses during play that are so annoying. And, yes, it's possible to damage a monitor by increasing the refresh rate if the monitor doesn't support that rate.
I'm pretty sure the little pauses are caused by disk access... the drive that your page file resides on may be nearly full or fragmented. If it's possible you might consider creating a partition on your hard drive just for the page file, about 1.5 to 2 times the size of the amount of physical memory on your system. Make the new partition the same type as your boot partition (i.e., if the boot partition is NTFS, the pagefile partition should also be NTFS), then move the page file. It takes a reboot to finish moving it. When you've checked to be sure it's been moved, you can delete pagefile.sys from the boot drive... it's just taking up a whole lot of space.
I'm running Windows 2000 and can give details of how to do it with this OS, not sure about XP etc.