What are you trying to save as a pdf ? Got some links or examples of ones that always or more commonly do it ? I "print to pdf" a lot, and I haven't seen this trouble. I wonder if its something specific that you are doing.
I've had a similar problem (I think) but I'm not sure it's Leopard. I pasted an image (actually a Filemaker button with text label) into a Pages doc and then converted to a pdf. Looks fine on screen in both Pages and Preview. But when you open it in Adobe Reader the text part of the image is compressed and garbled. Didn't notice the Adobe problem till it came back from the printshop similarly garbled - they obviously don't use Preview (or even Macs). But if your print problem comes from Preview then we have different problems.
Oh yeah,.. I heard about this. They are supposed to fix it by the end Q1 of 2008. Until then, you might be screwed. Sounds like you might need to shout at Adobe for being slow issuing the update and Apple for not giving Adobe the final release candidate of Leopard... and you can blame Jobs and the iPhone for the hasty release of Leopard.
You might try uninstalling Acrobat 7 and see if that fixes the problem.