No, the post I provided explained that the solpartmenu does not allow for menu item borders to persist due to some hardcoding allowing a selected item border. The DNNMenu has no hardcoding and therefore should allow for it.
So you have two options.
1) change some script in the spmenu.js file
2) use DNNMenu
1) What I'd recommend is updating to the latest menu (v1.6.1) by copying the solparwebcontrols.dll into your bin folder and the spmenu.js file to your controls\solpartmenu folder. You can get these files from my site or the latest version of dotnetnuke. This won't fix your issue but will update you to the latest menu with the best browser compatibility. Then open up the spmenu.js file and find this line
function spm_applyBorders(o, sStyle, iSize, sColor, t, l, r, b){
if (t) o.style.borderTop = sStyle + " " + iSize + "px " + sColor;
Change it to
function spm_applyBorders(o, sStyle, iSize, sColor, t, l, r, b){
return;
if (t) o.style.borderTop = sStyle + " " + iSize + "px " + sColor;
This will cause the menu to no longer support its hardcoded border issues. Normally I don't recommend changing script like this since it makes upgrading difficult. In this case, however, I don't anticipate changing the solpartmenu anytime soon. Instead I am focusing my efforts on the DNNMenu.
2) If your stuck on DNN 2.x this is not really practical. But if you are interested in upgrading, using the DNNMenu is pretty straightforward to substitute out. See this doc for more details.