Black stripe on rightclick's menu

[AdeC]

Hello,

The time has come for my first topic I've been lurking for some time on this forum, but finally I've found the question, that I was not able to find an answer for.
Like, probably, many many users of this forum, I have my CPU undervolted and GPU underclocked to the max using PowerPlay. As you can see in my signature, I'm using T42 with Radeon 7500.

The problem is, that sometimes, I can see the black stripe on the rightclick's menu in MS Office (here's the picture of this in Outlook, but I was also able to see the same in Picture Manager):



This stripe appears (sometimes) only when Radeon is underclocked with PowerPlay. I haven't seen it when Radeon is using its nominal clocking.
Has anyone idea, what's this about ? Should I worry ? It doesn't make my work harder or so and I also strongly prefer using NHC just like I'm using it now, but I do not want my Radeon to say "bye, bye"

Hope you know the answer