Thanks Mamba:
I did reset the globals to OFF
I deleted the smarty_cache, smarty_compile files and then recreated them with 777 chmod
Can't reset debug, nothing happens when I change anything in Preferences --> General Settings, it just saying "taking you back to where you were"
------------------------------
System Overview
XOOPS Version XOOPS 2.4.5
PHP Version 5.3.1
mySQL Version 5.1.41
Server API apache2handler
OS Linux
safe_mode Off
register_globals Off
magic_quotes_gpc Off
----------------------------------

Hello, I don't seem to be getting any response to my dilemma. Is there anyone out there who can help. I can only login to my site by checking the 'remember me' box. Once in I can't change anything in the Admin section. What has happened to my xoops site, it was working great before.
Please help

Last week I cleared out my cache/smarty_cache and smarty_compile files. This solved my original problem (topic: 6gb smarty_cache). Unfortunately when I login as admin I can't change anything. eg I go to Preferences change, theme and it doesn't change. If I try to upload a module, nothing changes.
I've tried changing php.ini to change 'register_global ON' but this doesn't help. I've repaired all xoops tables using phpMyAmin and still not change. I read somewhere that if I did an upgrade of xoops this may help, but I can't upgrade if nothing in Admin works.
Help!!

I've corrected the problems in theme.html and I can at least get into the website. there are still some issues but will hopefully sort these out myself.
Thank you

Yes the file system is the same as before. It is placed inside the xxx file which is outside the xoops folder in htdocs (as per xoops recomendations)
---------------------------
/opt/lampp/xxxxxxxx/xoops_data/caches$ ls -al
total 24
drwxrwxrwx 5 andrew andrew 4096 2011-01-17 10:48 .
drwxr-xr-x 4 andrew andrew 4096 2011-01-16 19:48 ..
-rw-r--r-- 1 andrew andrew 33 2010-11-08 18:24 index.html
drwxrwxrwx 2 andrew andrew 4096 2011-01-16 19:14 smarty_cache
drwxrwxrwx 2 andrew andrew 4096 2011-01-17 09:38 smarty_compile
drwxrwxrwx 2 andrew andrew 4096 2010-12-06 19:23 xoops_cache
---------------------------

Thanks Mamba for your speedy response. I deleted files xoops_data/cache/smarty_cache & smarty_compile. This certainly cleaned up my hard drive, however the website now doesn't load with this error message:
-------------------
This page cannot be displayed due to an internal error.

You can provide the following information to the administrators of this site to help them solve the problem:

Error: Smarty error: [in /opt/lampp/htdocs/newsletter/themes/xoops_thm_exnews2/theme.html line 17]: syntax error: unrecognized tag: /favicon.ico (Smarty_Compiler.class.php, line 446)
--------------------

I mkdir smarty_cache and smarty_compile with same permissions but still error exists, any suggestions as I can't even open the website.
Thanks

I've had a googlebot crawling thro my website for days now and filling up my harddrive. When I looked at the cache/smarty_cache file it was massive (6GB). How can I clean out this file. Can I delete it or am I asking for problems.

XOOPS Version XOOPS 2.4.5
PHP Version 5.3.1
mySQL Version 5.1.41

Thanks

Thanks Mamba & Ghia:
You have both been very helpful with my 'garbled' page dilemma. After we had all exhausted many options, I decided this wasn't a XOOPS error. I backtracked some of my ubuntu file changes and methodically worked thro' each one to see if it solved the problem, especially the php.ini file. Just when I was ready for quitting, I reverted the zlib.output.... back to their original state

; Note: You need to use zlib.output_handler instead of the standard
; output_handler, or otherwise the output will be corrupted.
;http://php.net/zlib.output-compression
zlib.output_compression = Off
;changed by andrew for files
;zlib.output_compression = On

;http://php.net/zlib.output-compression-level
zlib.output_compression_level = -1
;changed by andrew for files
;zlib.output_compression_level = 5

Voila, it worked and I now have my xoops back and running properly.

Again, many thanks and good luck with 2.5

Thank you: I also removed the "id=......" from the first two lines

As well as xoops running, I also have another private site for family tree. For both programs you can register and these are the results from both. The Family tree works without any garbled text. The xoops site is still garbled. I'm not sure if you can decipher the details and if it helps in any way

This is the info from the exim4 mainlog

Xoops register which sends emails but 'garbled'

2010-11-18 08:23:12 1PJ7GS-0001Fa-Km <= andrew.xxx@yyy.ca U=nobody P=local S=685
2010-11-18 08:23:12 1PJ7GS-0001Fd-PK <= andrew.xxx@yyy.ca U=nobody P=local S=1208
2010-11-18 08:23:13 1PJ7GS-0001Fa-Km => andrew.xxx@yyy.ca R=smarthost T=remote_smtp_smarthost H=yyymail.cg.yyycable.net [64.59.128.135]
2010-11-18 08:23:13 1PJ7GS-0001Fa-Km Completed
2010-11-18 08:23:13 1PJ7GS-0001Fd-PK => blobby@yyy1.ca R=smarthost T=remote_smtp_smarthost H=yyymail.cg.yyycable.net [24.71.223.43]
2010-11-18 08:23:13 1PJ7GS-0001Fd-PK Completed

Family tree register which sends emails and no problems

2010-11-18 08:27:45 1PJ7Kr-0001Ft-Sx <= nobody@yyymail.no.yyycable.net U=nobody P=local S=1294
2010-11-18 08:27:46 1PJ7Ks-0001Fx-2B <= nobody@yyymail.no.yyycable.net U=nobody P=local S=1288
2010-11-18 08:27:46 1PJ7Kr-0001Ft-Sx => norbut@yyy1.ca R=smarthost T=remote_smtp_smarthost H=yyymail.cg.yyycable.net [64.59.128.135]
2010-11-18 08:27:46 1PJ7Kr-0001Ft-Sx Completed
2010-11-18 08:27:46 1PJ7Ks-0001Fx-2B => andrew.xxx@yyy.ca R=smarthost T=remote_smtp_smarthost H=yyymail.cg.yyycable.net [64.59.128.135]
2010-11-18 08:27:46 1PJ7Ks-0001Fx-2B Completed