I usually have 10+ text documents loaded in the single Textpad instance that I run. Some of the documents would be minimized to the bottom, others would be open in various "mini-windows" inside the main Textpad window. To cycle through all the documents, I use ctrl-tab or ctrl-shift-tab, and it works great when I start Textpad.
At some point (I've yet to figure out how it happens since I use the same TextPad instance over a period of months), I find that when I use ctrl-tab or ctrl-shift-tab, I only cycle through all of the open documents. The ones that are minimized are ignored by the tab-cycle. However, if I hold down ctrl-tab (instead of pressing it), I watch the window focus cycle through all documents, including the minimized ones. Of course, since I'm holding down ctrl-tab, I have poor control of what document I land on when I release it. However, if I press ctrl-tab at this point, it jumps to an open document (i.e. back to cycling amongst only the open documents.
So, I find that I am no longer able to tab-cycle to the minimized documents. I've only found restarting Textpad to "fix" this (choosing to rearrange Icons or cascade/tile also seems to momentarily help). I've also noticed that when Textpad is in this state, when I click or select "Restore" of the minimized window, it would Maximize instead (after the maximize, if I click restore again, it'd go back to the window shape I was originally expecting)... which seems strange...
I am usually completely keyboard bound in TextPad... so this exception irks me to no end whenever it happens. But, I still love TextPad because it simply and reliably does everything I need.