SES Code P0102 - (MAF) Circuit Low Input

I have a 99 Astro and am getting a P0102 SES Code. I am on my third MAF with the last being purchansed in April of this year. There seems to be some correlation with fuel fill-ups and yet other times it could come on while driving in town or on the freeway. There is no noticable performance degredation and the SES light will eventually go off. I am using a K&N air filter, however, I have used both a Fram and Wix filter and still get the code. I have cleaned the MAF with electrical cleaner, I have checked for air leaks around the MAF and have read the information at:
http://www.obd-codes.com/trouble_codes/generic/p0102-maf-mass-air-flow-circuit-low-input.php

Has anyone else experienced this problem or have any ideas? Thanks!

Any air entering the engine unmetered can cause this, vacuum leaks especiall,y also the oil contamination issue with the K and N, but you probably eliminated that, is the K and N off, the sensor cleaned and the condition is still there? Lots of problems with parts stores rebuilt MAF's also. Check this link also.http://service.gm.com/gmspo/mode6/pdf/1999/99t43WXLD_yE.pdf

Update:
Well, since my last post I have removed the K&N Air Filter and replaced the MAF again (Old MAF still under warranty from Kragen). All connections have been checked and there are no air leaks around the MAF.

Current Situation:
Still getting the P0102 code which occurs after every fuel fill-up. Again, no performance issues and the SES eventually goes out eventually. This is just very annoying. Any help would be greatly appreciated. Thanks.