500 Server Error / PHP / MySQL

[LawsHosting]

I have a Soccer Prediction (php) script on a site of mine... Was running great until.........

Senario:
Currently have 497 entries in a MySQL table. However, if I add more to it (above 497), I get a 500 Internal Server Error. The page does list all of these rows by the way.

Is this a MySQL issue or.... saying that, it cant be as I've over 450,000 rows in another database (same server).

Any ideas...... I'm kind of stumped to say the least......
I know this isn't DA related, but if anyone has any suggestions

 

[LawsHosting]

I've fixed it by adding a LIMIT 450 to the query....... So, I'm now thinking it could be a server/memory/mysql issue?

php.ini's memory_limit is set at 35M