Two tricks to creating smaller ringtone files.
1. Use a good sound editor that allows you to create a "mono" file from a larger stereo file; allows you to change the bitrate of the file; and allows you to save in different formats.
2. Once you have gotten it nice and small, convert it to a wma. You lose sound quality, but on the speaker it's coming out of, you'll never be able to tell. MS has addins for WMP that allow the coversion very easily. Your sound editor might also.

I use Audacity.

Audacity will work, although it won't let you save as a .wma file.
Just save as an mp3 or wav and convert.
I also just found a site that has a ton of great ringtones already created in numerous formats.
http://www.personalwireless.org/tools/Ringtones/

Nice site, not a lot of tones though :(

So ur basically putting whole songs into the /Windows/Rings folder? Don't do that, make them around 25seconds long. Infact, go to the "Ringtones" section of PPCGeeks and test try a few of the ringtones on there... I even uploaded the one i used Ludacris - Girls Gone Wild. Now u don't have to use it or anything, just go to the section download a few of them, try them out, making sure u keep it in the main memory and not the SD card, and see how the phone reacts. This way u can tell if it's something w/ ur phone or if it was the SD card. My guess would b the SD card is causing the prob.

Like i said, i've uploaded the one that i use and it works fine for me, I do have a few others, and they all come in fine, i always put them in the Rings folder which is located inside the Windows folder.

Good Luck

I posted the Slot Cycle Index hack in the wiki a few weeks ago, It works great set on 1 for me, and will help.

But the biggest problem I think your having is going to be resolved with the files gatting optimised as discussed.

Thanks for the help. I made my tones less then 20 sec, put them in main memory, changed index slot to 1. and i get a faster respond time. Now i just have to free up some more main memory, so i can put more tones :)