I'm also getting the error, but only when I run the app in the simulator. I am using the iPad 5.0 Simulator, iOS 5.0, ESRI iOS 2.0 API.
I get the following message when I try to zoom in too quickly:
2011-07-18 10:26:38.285 BioMosaic[1349:6703] *** AGSTileRequestOperation 0x8168e20 went isFinished=YES without being started by the queue it is in
2011-07-18 10:26:38.292 BioMosaic[1349:6703] *** AGSTileRequestOperation 0x816c220 went isFinished=YES without being started by the queue it is in
2011-07-18 10:26:38.293 BioMosaic[1349:6703] *** AGSTileRequestOperation 0x816f760 went isFinished=YES without being started by the queue it is in
2011-07-18 10:26:38.295 BioMosaic[1349:6703] *** AGSTileRequestOperation 0x816fc70 went isFinished=YES without being started by the queue it is in
2011-07-18 10:26:38.296 BioMosaic[1349:6703] *** AGSTileRequestOperation 0x8170180 went isFinished=YES without being started by the queue it is in
2011-07-18 10:26:38.297 BioMosaic[1349:6703] *** AGSTileRequestOperation 0x8170690 went isFinished=YES without being started by the queue it is in