Server crashes every day

[dronox]

I do not have a swap partition in this vServer.

Well, htop sais that 203MB/534MB are used (I'm wondering about the 534 because I only bought 384MB at my hoster).

On the server there are running some additional daemons:
subversion with 2 repos
imap and smtp (1 mail account)

I removed amavis, spamassassin, postgrey, bind9.

On my apache there are running 4 pages at the moment:
-webmail client (roundcube)
-ispcp admin login
-1 project management (dotproject)
-personal homepage with little-middle php scripts

Regards
Dustin

edit:
For subversion access I use the WebDAV plugin in Apache2...could there be a problem with the memory usage?