Is my freon leaking or do I have another problem?

There is a leak in the system. The dye will show where the leak is. It may be hidden inside the dash, so they may have to do some dis-assembly to find it!!

If the dye was added last year, and the car not checked for 6 months, the dye may been washed off by weather or car washes. You may need to have the dye redone and bring the car back in two weeks to see where the leak is!

You say dye was added. If you cannot see the dye anywhere out under the hood, you may need to do some investigating. Check the condenser. It's out in front of the radiator. If it doesn't show there, it could be the evaporator - It is in a compartment either under the hood or under the dash. Some mechanics have a way to either use a special light or a special 'sniffer' to check for leaks. The places to check are the clutch of the compressor (there is a seal behind it), the relief valve (if there is one) and all valves where the gauges are hooked up. The reason they may not have found the leak is because they were hooked to the system at the time. They are like the valves in the tire; they leak too. If all else fails, you need to check out the evaporator

Sounds like a fairly good-sized leak...if dye was added, I'd be tempted to get a black light, and see if you can find the leak. It may possibly be in the evaporator, however, and you can't see in there, as it is completely enclosed.

There has to be a leak, and it is most likely occurring inside the compressor where the die does not make it back out, and or it is leaking in the evap coil where you would never see the die because it is hard to get to and absorbed by the coil fins.

if it's a high mileage car, consider it to be the compressor.

Yes you have a leak. Take it to a shop that does a/c repair annd they can check at the vents with a halogen leak detector to see if the evaporator is leaking.