Corrupt read only tables

How can a read only MYISAM table become corrupt?

I have to do a myisamchk -r approx. once a week as the table gets marked as crashed.

I can't see how this is happening though as no changes are being made to it, it's read only.

It's running on mysqld-nt version 5.0.51b, the same table running on a mac and a linux box have not done this, so far.

You sure the drive is healthy?

The recovery plan is following

Split corrupted InnoDB tablespace into pages; sort the pages by type and index_id
Fetch records from PRIMARY index of the table
DROP corrupted table and create new one
Load records back into MySQL

Also you may visit the branch where the similar issue was resolved http://www.sqlservercentral.com/Forums/Topic1664684-384-1.aspx