I posted an issue into the forum yesterday about the nasty habit TextPad 5.0.3 has of messing up the cursor movement after pressing End on any line longer than the width of the window.
Lo and behold, I got a response that I thought anyone experiencing this problem might be interested in. It is attached below. I have tried this version, and, at the least, this particular issue is corrected. I'm not sure why this is not available from their Downloads page or why they have not made this more publicly known, but I hope you find this helpful.
Please try the latest TextPad build. Just overwrite the original .exe file in your TextPad installation folder.
<<link removed by moderator ... not available for general distribution>>
I am so sorry to have provided false hope. For some reason, the link has been removed by Helios. Anyway, there is definitely a version of TextPad that has this issue resolved. Maybe each user has to ask for it individually.
If you are following the link to this post from my response on other posts, at the time, the link was available, but it has since been removed. Sorry.