Oh, please Mac- tell me you're using MySQL
and not MSSQL. That alone could explain your entire problem.
*open source- enough said. I'll take OSS over closed source any day.
*cross-platform. AIX, BSDi, FreeBSD, HP-UX, i5/OS, Linux, Mac OS X, NetBSD, Novell NetWare, OpenBSD, eComStation , OS/2 Warp, QNX, IRIX, Solaris, SunOS, SCO OpenServer, SCO UnixWare, Tru64, Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, and the 32-bit version of Windows Vista
*less resources required than MSSQL
*more reliable than MSSQL
Community Edition is free, licensed under the GPL. That's all you need- the main advantages of Enterprise Edition are the tech support and also support for more concurrent connections. IPB uses very few connections to the DB, well under the approximately 500 limit in Community Edition.
I also can't stress the importance of a backup SQL server. Either doing live mirroring, or periodic scheduled backups. Both methods can be configured fairly easily. Don't even *think* of mentioning cost, as some of the backup systems I've made in the past were P-333 systems with as little as 128MB/RAM. My current backup SQL server is a Celeron 2.66GHz that I literally made out of spare parts, running eComStation with 256MB/RAM. It outperforms the three quad-core Vista system (all with 1-2 gigs RAM) I've pitted it against.
Moral: for a machine making backups, you don't need blazing speed or all the "bells and whistles." Use older (read: inexpensive) hardware and a matching OS and you'll still get the performance you need.