When I first got the warning, I just clicked "OK" to "Deny Access" to the file, as my experience with AntiVir has been that it cannot delete infected files when it first locates them. I usually check the log and delete them later or use a dedicated removal tool for that particular virus. I try to be careful so I don't run into this problem very often.
In this case I tried to view Drive M, which was the Astak's internal memory at the time as I had removed the SD card I used to flash the firmware at that point, so there is no question that it was not the memory card. However, I could not locate the file in question. I don't have any Linux distro's installed at the moment, so I don't know if I would have better look trying to view the memory of the reader using Linux, but in Windows XP I use folder settings where no files are hidden.
As I clumsily reported, I repeated the connect sequence several times to confirm that the reader was triggering the alert, but on the final instance tried the option from AntiVir to delete the file, and surprisingly it didn't offer it's normal "sorry--can't do that now" message and seemed to have deleted the file. I cannot say for certain it did, as I could never see autorun.inf in the first place. But ever since then I have been able to connect the device without receiving any warnings.
It doesn't sound as if this is a known issue. I'm additionally curious if it was introduced during the firmware upgrade process. Even though the file I installed was probably the same version, perhaps it was a different build copy or something? I downloaded it from theEZReader.com website a couple days ago. I suppose once the new firmware comes up, and if the problem resurfaces, that would be a clue.
Anyhoozle, things seem to be humming along nicely at this point.
Thanks for the input, guys!