Maybe your off by a tooth when you lined up the sprockets.
You might need to do a cylinder leak down test instead of just the compression test.. take out plugs, get #1 cylinder to TDC, and then pressurize that cylinder... find TDC by putting a pen in the spark-plug hole and turning the engine manually until the pen comes to it's very highest point before sinking in again... this is after you confirm your on the compression stroke of course....
If you have a vacumme leak, then you must have knocked something when doing this job... grab a propane torch and run the motor. Sweep the torch around and listen for changes in idle.
Lastely, check out the PCV valve grommette. Just my .2 cents... im gonna go with a vacumme leak though, just because the idle problem is new after the timing belt, where as a carbon build up would have been evident before as well.