Basically there are four parts to the bot. Understanding the four parts will help you diagnose issues like that and know how to fix them.
1. The core - this is the actual HB or GB that you download and run. The central engine that ties it all together.
2. The customclass - this is a c#-written file that contains the logic and instructions of what your character should do anytime its in combat or is about to pull. These are open source, and there are many available.
3. The profile - this is an xml file that contains the locations, enemies, vendors, and quests that your character should do at a given level. Also open source, and many available.
4. The plugins - these are c#-written files that perform extra functions while HB is running, like stat monitors or generic spells (lifeblood). Open source, quite a few available.
In your case, it sounds like an issue with #2. I'm guessing you're using the default Mage.cs (if you haven't changed it, then you are) that is included with HB. The included CC's are meant to be basic, but stable. I'd recommend giving some of the 3rd-party Mage CC's in the forums a try to see if they work better for you.
http://www.buddyforum.de/forumdisplay.php?44-Mage-CCs
Mephiles is brand new and I don't have experience with it, but CodenameG does great work. ProjectE is his older version which was very good as well, I'm not sure if Mephiles was meant as a replacement or not.