Core

I know that deprecation log can be disabled and that they're simply warnings.
what astounded me is that all the warnings about "t3lib_div::int_from_ver() " come from system extensions or core files (see attached file).

looking again at the file I attached, I see that there are problems with 2 extensions: t3jquery and templavoila (both are the latest version), but what about lines like this:

24-04-12 12:33: t3lib_div::int_from_ver() - since TYPO3 4.6, will be removed in TYPO3 4.9 - Use t3lib_utility_VersionNumber::convertVersionNumberToInteger() instead - require(.7.0/typo3/init.php),.7.0/typo3/sysext/tstemplate/ts/index.php#41 // include(typo3conf/temp_CACHED_ps4a74_ext_tables.php),.7.0/typo3/init.php#376 // t3lib_div::int_from_ver#2132 // t3lib_div::logDeprecatedFunction#888 (.7.0/t3lib/class.t3lib_div.php#885)

24-04-12 12:35: t3lib_div::int_from_ver() - since TYPO3 4.6, will be removed in TYPO3 4.9 - Use t3lib_utility_VersionNumber::convertVersionNumberToInteger() instead - require(.7.0/typo3/sysext/cms/tslib/index_ts.php),.7.0/index.php#78 // require(.7.0/t3lib/config_default.php),.7.0/typo3/sysext/cms/tslib/index_ts.php#83 // require(typo3conf/temp_CACHED_FE_ps4a74_ext_localconf.php),.7.0/t3lib/config_default.php#1086 // t3lib_div::int_from_ver#1084 // t3lib_div::logDeprecatedFunction#888 (.7.0/t3lib/class.t3lib_div.php#885)

or

24-04-12 12:32: t3lib_div::int_from_ver() - since TYPO3 4.6, will be removed in TYPO3 4.9 - Use t3lib_utility_VersionNumber::convertVersionNumberToInteger() instead - require(.7.0/typo3/init.php),.7.0/typo3/mod.php#34 // include(typo3conf/temp_CACHED_ps4a74_ext_tables.php),.7.0/typo3/init.php#376 // t3lib_div::int_from_ver#2132 // t3lib_div::logDeprecatedFunction#888 (.7.0/t3lib/class.t3lib_div.php#885)

24-04-12 12:33: t3lib_div::int_from_ver() - since TYPO3 4.6, will be removed in TYPO3 4.9 - Use t3lib_utility_VersionNumber::convertVersionNumberToInteger() instead - require(.7.0/typo3/init.php),.7.0/typo3/ajax.php#55 // include(typo3conf/temp_CACHED_ps4a74_ext_tables.php),.7.0/typo3/init.php#376 // t3lib_div::int_from_ver#2132 // t3lib_div::logDeprecatedFunction#888 (.7.0/t3lib/class.t3lib_div.php#885)

They don't seem due to 3rd party extensions...:S
I also enabled the workspace sysext and obtained:

26-04-12 16:26: t3lib_BEfunc::isPidInVersionizedBranch() - since TYPO3 4.4, will be removed in TYPO3 4.7, as branch versioning is not supported anymore - require(.7.0/typo3/sysext/recordlist/mod1/index.php),.7.0/typo3/mod.php#45 // SC_db_list->main#499 // template->getVersionSelector#289 // tx_version_gui->getVersionSelector#1783 // t3lib_BEfunc::isPidInVersionizedBranch#131 // t3lib_div::logDeprecatedFunction#3960 (.7.0/t3lib/class.t3lib_befunc.php#3959)
26-04-12 16:26: t3lib_userAuthGroup->workspaceVersioningTypeAccess() - since TYPO3 4.4, will be removed in TYPO3 4.8 as only element versioning is supported now - require(.7.0/typo3/sysext/recordlist/mod1/index.php),.7.0/typo3/mod.php#45 // SC_db_list->main#499 // template->getVersionSelector#289 // tx_version_gui->getVersionSelector#1783 // t3lib_userAuthGroup->workspaceVersioningTypeAccess#157 // t3lib_div::logDeprecatedFunction#910 (.7.0/t3lib/class.t3lib_userauthgroup.php#909)

whoa, now it's much clearer!
It seems that the "guilty ones" are
t3jquery
rzcolorbox
tt_news

I'm not able to reproduce the initial error, which was:

24-04-12 10:26: file_list.php is deprecated since TYPO3 4.5, this file will be removed in TYPO3 4.8. The filelist module is a system extension now, do not link to this file.
Referer: http://typo3.test.47l/typo3/file_newfolder.php?&target=%2Fvar%2Flib%2Ftypo3-sites%2Fdummy-4.7L%2Ffileadmin&number=3&returnUrl=file_list.php%3Fid%3D%252Fvar%252Flib%252Ftypo3-sites%252Fdummy-4.7L%252Ffileadmin%26imagemode%3D1

attached: the last log file deprecation_b4d3bd3772_last.zip

I'll disable the deprecation log for now, since all these extensions are essential for me.
thank you for your support