missing app icons after restart?

[Guest lobespear]

when i restart the phone, a random selection of my self-installed apps don't have their icons displayed, instead they just show the default android image. each time i restart, it's a different set of applications, but only ever the ones i have installed myself (on external sd card). the sd card itself is a class 10 32GB sandisk, so i can't believe its a sd card performance/data transfer rate issue. i dont want to install all the apps back on the internal memory again, so i'm wondering if anybody else has experienced this and how did they resolve it?