Let me start off by saying that this is a custom plugin. I am doing it for a client so I may not be able to share the source code.
Basically, I have implemented several shortcodes for this plugin. Individually the shortcodes work great. However, if I add in multiple shortcodes on a single post/page, only the first shortcode works. The other is ignored entirely, or simply shows the text for the shortcode itself (i.e. [my_shortcode] is shown as text).
I read through the support forums, as well as some bug reports for WordPress and found a bug similar to this reported in a previous version (2.8.x?). The fix was to place a single space in between the shortcodes. I have tried this to no avail.
I've checked my code and rechecked it, though I am yet to come up with a solution. Is this a common issue? Perhaps a bug similar to the one that was reported in an older version of WordPress?