After scrounging around my stock OpenACS 3.2.5 install, it looks to me that in the
package-patches template file that
$patch_description should be run through
util_close_html_tags to prevent this error. (I'm assuming that the SDM on openacs.org is using a template to display the results. I could be wrong, of course.) In the stock 3.2.5 install, this change is on line 14 of
package-patches.plain.adp.
Hopefully someone with actual authority (which isn't me) will be willing and able to make this correction.