bad plugins?

I have a problem with (at least) two plugins: wp plugin manager (1.6.4.b) and wp-contact form (1.0)
both of these plugins seem to have problems saving settings.
for example, wp-contact form works, except it doesn’t save the destination email adress and message settings
similarly, plugin manager doesn’t save the ftp setting i specify.
I’ve checked the wp-content folders, and they are set to chmod 777.
I am using the 1.5 release version of wp, and the following plugins are installed & enabled:
AcroPop 1.0
Author Highlight 1.0
Dashboard Options 1.3.1
Paged Comment Editing 0.2
EzStatic 1.9.1
FancyTooltips 1.2.1
Get Author Profile 0.2
PHP Exec 1.3
Post Updated R1
Search Pages 0.1
Structured Blogging 0.51
Subscribe To Comments 1.5
WP-ContactForm 1.0
WP Plugin Manager 1.6.4.b

Thanks, Jack