MySQL database limits?

[trendless]

I'm having some trouble with a program I'm running on XAMPP. It seems that when I start to approach 200 unique items saved to the database it stops allowing me to create new unique items. Is there something in the implementation of MySQL in XAMPP that could be causing this (php hardening etc)?

The only customization that I've done is add ZendOptimizer which is required for the program (encrypted scripts). Suffice it to say, I'm a lamp noob and wouldn't know where to begin customizing, so I certainly haven't been messing around

[Wiedmann]

It seems that when I start to approach 200 unique items saved to the database it stops allowing me to create new unique items.

Well, MyISAM is using table locking:
While you insert/update many rows, the table is locked for other inserts.

[trendless]

Wouldn't that affect the first new unique item I try and add to the database if it were going to affect any; ie I would have issues right from the start, not after some data has already been added?