Thank you for contacting Support.  I've reviewed the region and what I've found so far is that it has been online for about 10 hours now, and I was still able to rez without issue.  I put out two highly scripted motorcycles without any problem.

That said, we have been tracking this sort of behavior in other regions aside from yours.  We've got a little bit of information, but not enough yet to be able to to identify (and solve) the root issue.  Here's what I'm seeing in your region:  Right now, though I'm able to rez, the physical memory allocated to the region is 214.7MB.  That's a lot.  It's so much, in fact, that it's near the limit allowed for a Homestead region (256MB).  Once that limit is reached, or close to ( > 90%), internal region safeguards will shut down all rezzing.  This is what is happening to you.

This system was designed to assist with griefing scenarios to prevent the region from allowing more objects once it was already near unstable levels.  However, it should take a lot to push a region up to that level (like a griefing attack).  The fact that your region is creeping up to that level after each restart and staying there (if I understand your description correctly) is a problem.  Most regions, even busy ones, run around 40-80MB.  You can verify your region's current physical memory allocation by using the Statistics Bar (shift + cntrl + 1 in most viewers); you're looking for the stat labelled Memory Allocated in the Physics Details section about a third of the way down.

What does all of this mean for you?  Well, in the short term, it means 2 things:

-I don't have a permanent solution to this issue.  This is a bug, and needs to be reported as such to our developers.  They're actively gathering information on this issue, and your input would be invaluable.  Particularly, paying attention to when (and by how much) the Memory Allocated stat starts to increase is exactly the sort of information they need.  In the meantime, restarting the region remains your best work-around.

-You're (probably) not doing anything wrong on the region.  We have a very circumstantial theory that the memory leak may be caused/worsened by particle emitting objects/attachments, but that's completely unconfirmed and is incorrect behavior in any case.  But it may be something to look out for in the short term.

In the long term, it means that we're working on a permanent solution.  With your assistance (filing a bug report and working with the developers there), hopefully we can get it fixed faster.  :)

I hope this information helps, and if you have any further questions or concerns about this issue, please do not hesitate to contact me via this case.

Regards,
Reed Linden