ok here is abit of NEW SCHOOL on swap/virt ram thinking.
if you are sub 512M ram, then double or quad the swap/virt to physical ram.
so in the OP case with only 256M, he/she/it should be running 512 - 768 (might be off a tad on the high end) as windows will NOT allow for 4x so you are just fubar when it comes to really pushing your swap/vert mem.
best option is to, as mentioned several times, max out your physical ram to 1G, or best your MB will handle. you may only be able to run 768 or 512M, depends on your MB.
if you have 512M - 768M of ram, then a 1 to 1 ratio of swap/vert to physical is ok, if you are over 1G of ram, then you can cap your swap/vert at 256M, 512M if you think you really need it, but odds are you WILL NOT/SHOULD NOT need more then 256M swap/vert if you have 1G+ of physical ram.
RAM is way faster then any hard drive out today except for the ramdrives (google for them, they are DDR chained together to form a hard drive, really kewl, but not worth the cash) so to waist performance in swap/vert memory instead of phsyical ram is just that. much slower performance.
the old 2 to 1 ratio comes from the days with ram was measured in K vs M like it is today and was still required in the win9x days with 512M being the hard cap without major hacks to the registry in windows. with todays systems (hardware and OS) being able to handle much more ram, there is less and less need for swap/vert memory to be used.
you will waist HD space, and decrease the overall performance of your system if you have more then 1G of ram with a 2 to 1 ratio for swap/vert memory so you can get away with much smaller swap/vert partitions if you have more physical ram.
so to the OP, max out your vert. memory or upgrade to the max your MB can handle.
good luck.