Isodumper do not currently make sure write buffers are flushed before saying it is finished.  So user may pull it out before it is written (despite having been "verified" ?!

Suggestion, tip from tmb: "eject" informs the kernel that the device should be dismounted, and then the kernel flushes out the block-level writes before dismounting it. 

So before telling user it is done, issue "eject /dev/sdx" (change x)

Additionally, verifying the write can of course only be reliable after this flushing, so stick should be "ejected", then verified.

Here some trick is needed:  After ejecting the stick fdisk -l do not list it and trying to write using dd to it i get error No medium found.

(Sidenote: Launching isodumper at that moment it list the stick anyway)

So somehow /dev/sdx need be "unejected" however that is done.