Its a problem that plagues all bikes, but suzukis seem to be the most prone to it.
Anybike that doesnt have a dry sump (buels) holds the engine oil in the pan at the bottom of the engine. There is a pickup for the oil pump, which then pumps the oil on the bottom of the pistons, into the crank shaft, and everywhere else it needs to go. When you pop up the front wheel, you are in effect tilting the engine. The oil in the pan, all goes to the back of the pan. Now, if the oil pick up for the pump is in the front of the pan (and suzuki places them far forward) then the oil pump cant suck up any fuel, and so there is no fuel going to the rest of the engine.
Before you get all scared that wheelies are so bad for you engine...
If its a quick wheelie, then 2 things save you. 1. There is still oil in all the lines, so there is still oil being pushed into all the parts that need it. It takes some time for all those lines to drain.
Oil is really viscous, so it remains on all the necessary parts, and doesnt drain off immidiatly. So the parts are still lubricated, just that the oil isnt being replanished.
So its only a problem if you ride mile plus long wheelies. Or that slow speed stuff. Really its a matter of how long the bike is on one wheel not how far.
The relocator maindr is talking about, is just a piece of 0.25" copper tubing (with some connectors) that makes the oil pump suck oil from the back of pan instead of the front. That way you engine always has a supply of oil regardless.
Another method of remedying the problem is to add extra oil. the oil level in the pan is higher, thus its less likely to "expose" the oil pickup. This is not without risks, as the oil pressure rises with more oil, and you risk busting a few gaskets. There are specific rubber plugs, that are made to bust when the oil pressure rises to high. They are there to protect the engine seals from going. They are cheaper, and much easier to replace.
Hope that helps