Spa phone searching for spaM:A:C semicolons! in its filename

Question

Provisioning a new set of spa504G phones. I've always used 
for spa504G.cfg, the phone finds it. I've always used:
<flat-profile>
<Resync_On_Reset>Yes</Resync_On_Reset>
<Resync_Periodic>3600</Resync_Periodic>
<Profile_Rule>tftp://ipaddress/xml/spa$MA.xml</Profile_Rule>
</flat-profile>
The new set of phones weren't provisioning, so I ran a tcpdump on the tftpserver. Sure enough, for the first time ever, the phones are looking for:
spae8:ed:f3:6b:48:b2.xml instead of spae8edf36b48b2.xml. I copied the xml to use colons and sure enough the phone provisioned and connected to my pbx.
So... how do I make it stop doing this? This is a tragedy, you have no idea how difficult it will be to get more spa phones at this point.
A bit more info:
I also tried <Profile_Rule>tftp://ipaddress/xml/spa$MAC.xml</Profile_Rule> in the initial config file.
The phones came with firmware 7.5.2 and I always upgrade to 7.5.3 using:
<Upgrade_Rule ua="na">($SWVER ne 7.5.3)? tftp://ipaddress/sw/spa50x-30x-7-5-3.bin</Upgrade_Rule>
however, this time it's not upgrading, either.
Any ideas? Anyone else seen this before? How can I make it stop, using special characters in the filename is not going to work for me.

Answer 1

<Profile_Rule>tftp://ipaddress/xml/spa$MA.xml</Profile_Rule>
the phones are looking for:
spae8:ed:f3:6b:48:b2.xml instead of spae8edf36b48b2.xml
Well, the $MA macro should expand to MAC with no colons. And it work this way on all firmware versions I meet. So unless it's a bug specific to 7.5.2 version, it should work. I can't test this particular case as I have no phone with 7.5.2 firmware.
The phones came with firmware 7.5.2 and I always upgrade to 7.5.3 using:
<Upgrade_Rule ua="na">($SWVER ne 7.5.3)? tftp://ipaddress/sw/spa50x-30x-7-5-3.bin</Upgrade_Rule>
Wrong. It's not possible to upgrade pre-7.5.2b version to post-7.5.2b version directly. You should upgrade to 7.5.2b first. Read release notes. Also, you should consider upgrade to latest (7.5.6) version rather than to somewhat ancient 7.5.3.
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