Jacks on one end and plugs on the other should work fine, as long as you have both ends of the cable wired the same. I've used this arrangement in several cases, and have never had a problem with it that wasn't caused by a mis-placed wire. In your case, it sounds like you have something wired wrong. Either you have the plugs wired as 568A and the jacks wired as 568B, the other way around, or something totally different.
Check out the "How to make CAT5 Cables" link off of JackMDS's first link for more information regarding the proper way to wire the plugs; the keystone jacks should come with their own instructions for wiring, though there is also the "Keystone Jacks" section on that same page.
JW