Paypal buttons issue

I think I have had every problem regarding Paypal buttons ever reported on this forum – white space above the button, buttons disappearing on page, invalid regular period error, unable to verify post vars error, etc. And I have tried all of the “fixes” suggested as well, all to no avail. I doubt I am the only one… Most of the button problems have to do with WordPress filters trashing the button code. In particular, in the 4-5 fields of the button code that includes php to get user data, a quote is turned into a curly quote. If your button seems to be invisible or moved, you can View Source in your browser and you will see the illegal bpmn syntax. I tried disabling all the plugins, but that didn’t work. I actually think it’s the theme – InFocus, the one recommended by s2Member! Whatever…

I tried the paypal-generated buttons. They work, but not for the free trial -> paid upgrade scenario advocated by s2Member and which I like. I tried the TrueEdit plugin recommended by users on this forum, and that works partially, with the button longcode (not shortcode). But it does not run the php, just passes it as a literal string. I tried a bunch of php plugins to fix that, and I finally found one that worked: It’s called Post Snippets, and creates a named shortcode for each php fragment. This finally worked (I think). The button is not encrypted but at least the test payments are going through on paypal and the user level is promoted properly.

Judging from this forum, this Paypal button issue appears to be such a frequent problem with s2Member, and their support seems so generally unhelpful about it, that they really ought to improve this aspect of the plugin. Specifically, there should be some approved configuration of wordpress (themes and common plugins) that is known to work.